Okay...
Mystic Theurge:
Skills: Knowledge (arcana) 6 ranks, Knowledge (religion) 6 ranks.
Spells: Able to cast 2nd-level divine spells and 2nd-level arcane
spells.
So, you take Cleric 1 and Versatile Spellcaster feat. All clerics can spontanously cast Inflict or Cure spells. You drop two 1st level spells to cast a 2nd level Inflict/cure, Bam, you now qualify as a 2nd level Divine spellcaster.
Next, you take Sorcerer 1. Now, you need heightened Spell. You used Versatile Spellcaster to cast a Heightened version of a 1st level spell you know. Bam, you now qualify as a 2nd Level Arcane Spellcaster.
Finally, you take a level in Wizard. Buy up the skills you need to the levels nessisary to qualify for Mystic Theurge, And then you got some choices to make.
Mystic Theurge is a good start, but at some point you might wish to put that level or sorcerer to use. May I recommend branching out into Ultimate magus at some point. Or consider Arcane Hierophant at some point, if you haven't advanced your Divine and Arcane classes far enough for your tastes.
The upside of this is, by level 4, you are advancing in both Cleric and Wizard instead of starting at level 7 (BTW, consider Alternate class features for all three base classes. Maybe you can squeeze something out. More certainly give up the familiar. Twice. It won't be giving you anything, anyways. Cloister Cleric Springs to mind. I think you can give up the familiar to get rid of full round actions on spontainous metamagic modifications for your sorcerer.)
You'll be two levels behind a Straight up Cleric or Wizard, but you won't be three levels behind on both if you go the standard Mystic Theurge route. AND you'll have some Sorcerer Spontainous spells to play with. Avoid Combat Spells for the sorcerer. Your sorcerer spells won't scale up with level, but you can add some useful spells in there. Feather fall is not only useful for falling, but it's the lowest level spell you can cast as your swift action. This is a good way to trick people who are holding their action to disrupt your spellcasting into wasting it on a pointless spell.
Consider Wizard Specialization for the extra spells, or an elven generalist if your goal is to just have access to ALL the spells.
Now, the problem is, maybe your DM isn't playing with Races of the Dragon, then versatile Spellcaster is out. In that case, DO NOT PLAY A MYSTIC THEURGE.
Seriously. I had one player do it, he did NOT use the Versatile Spellcaster feat and it was a huge drag on the whole party. He got killed. Twice. He eventually, when the game reached epic level, start to hit his stride. As a Wizard/Cleric/Mystic Theurge/War Weaver/Dweomerkeeper, he's really turned into Mr. All-Day-Buff, and You-will-Become-INVULNERABLE for the next hour, but it was a painful few years.
That said, if your DM will allow it, let him know it will be about 13 levels before you get disgusting. The one thing I noticed is that for all his many spells at his disposal, One POWERFUL spell would have been much better, then twenty sucky ones. BTW, you do have the stats for it.
That said, Monk might be a cool choice. Go with Dex primary, then load up on feats that give you AoO against things like, Oh, someone trying to hit you. Get a reach monk weapon. Take 10 attacks a round before your turn.
Or go with a larger then man-sized race and a Great Spear. Reach 20'. Take Cleave/Great Cleave and put everything into being a fighter who does a ton of damage in one shot. Load up on the cleave feats, like taking an extra 5' step everytime you activate cleave. Wade through low level NPCs like Moses parting the RED sea. (Red! Get it?) tack on a level or two of barbarian. Call yourself Oog. Act stupid, but be really smart.
Make a crit bunny. Scimitars and feats to increase your crit range. Two handed weapon fighting. Rend feat. Whir.
Go archer. Get Order of the Initiate as soon as possible. Shoot everything with an arrow as quickly as possible.
Go for Creation Feats. Get the feats that reduce creation feat costs. Take classes that reduce costs. Get the spell that allows you to use other people's XP to make things. Be the party armorer. Make everything Class and Alignment specific for the 30% reduction. Scribe Scroll, Craft Wonderious Item, and Craft Arms and Armor should cover 90% of the permanent magic items your fellow players might want.
Now...
Extraordinary Artisan Feat -25%
Magical Artisan (Pick Wonderous Items) -25%
Limited Class/Alignment -30%
Making it yourself...
So for every 1000 gp retail cost, you can make a magic item for...
GP: 196
XP: 7
And remember:
"In general, if you wind up with a fraction, round down, even if the fraction is one-half or larger. For example, if a fireball deals you 17 points of damage, but you succeed at your saving throw and only take half damage, you take 8 points of damage."
So, that means, if it costs 1,999.99 gp to make a magic item, it is only one day to make it. So, to reverse that...
You can make any Wonderous Magic Item that costs 5079 Gold in one day. Which covers just about every +2 stat enhancement item, +2 ring of protection, +2 cloak of protection. You can create magic items that add luck bonuses, Dodge bonuses, Circumstance bonuses, Blah Blah Blah. I leave the exact number of buffs you can stack up to the apt pupil. As a note, the Monk in my player's party achieved a touch attack AC of 70+ and a base AC in the triple digits after the casters get done with buffing the party. A great deal of that is from the Wiz/Cleric being a crafting bunny for the first 15 levels or so.