If you want to go with a Gish type character, Go Dwarf for this. Crusader 1/Wizard 4/JPM 10/Abj Champ 4/Rune smith (Races of Stone) 1. Now you can cast spells in Heavy armor while dealing out decent damage.
Make sure you grab that Stance that heals you 2 pts per strike, and your set. The CL will suck, you may not get 9th level spells but you sure could try it. Despite the mechanics of the Crusader its got the best funness of all the classes.
However, if you want to go with synergy and you dont care about spells much and want some of the best buff spells to make you a monster in combat.....Dwarf Saint, Swordsage 4 (Unarmed variant if you wish), Fist of the Forest 1, Deepstone Sentinal 2, Swordsage the rest of the way. You get Wis to AC 2x, Con to AC 2x, (You can drop your need for Dex, because once you get flatfooted your AC drops by 1 of your con mod bonuses), Boost Con, Wis and Str. Con and Str being priority, You can boost your wis up to squeeze out another point or two of damage. Grab shadowblade Feat and now you can add your Wis to Damage
with all shadowhand weapons.
If you do it right you can get good fun out of it and 9th level maneuvers, not to mention you can get a stance that allows 2pts to AC each miss, (Which means if a bad guy misses you 10x thats 20pts more to AC for one round). Then theres the 9th level ability for the swordsage maneuver that allows you to do insane ability damage on a successful save, but 15d6 on a failed save. If I remember that maneuver correctly.
Thats synergy for ya. If you really want to get some real good fun out of things
, PIXIE!!!!!!!!!! -4 str, +8 dex, +0 con, +4 Int, +8 Wis (I think), +6 Cha. SR, Tiny size, natural invisibility. Tag on Swordsage, YEAH!. Do LA buy off 1pt before twenty but!! you do get 9th level maneuvers quite eeasily, But thats if you dont have a Bastard DM like my group tends to have. If you got a good and nice DM, you can pull that off easily.
Or just play a Dragonwrought Kobold Metamagic specialist Sorcerer/Dragon heart mage/Abj Champ
. Oh the Sorcerer has to be a Battle Sorcerer to pull off the Abj Champ lol. But yeah, thats my 10 cent thoughts.
PS: that idea with the Crusader, do it on a Warforged and give him immunity to crits and such at 6th level
. THEN!!!!, get him up to Crusader 16/Warforged Juggernaught 4, grab that stance that heals you per strike. Now get a Wizard and cleric to buff you up, fly straight up, then roll up into a ball and try to cancel the spell to intentionally fall 200ft to the ground. That way a Gargantuan (Giant Size Wujen spell will work perfectly), but anyways, drop from 200ft up in the air, take the 20d6 damage. THEN!! you could argue with the DM that you struck all the goblins and such underneath you with your body instead of the Sword, and hit like 20 guys, in the process. You could get a average 40-50 damage done to you sure, but you could argue that you struck those 20 guys to heal that 40 damage back
. And then getup and bash the goblins who survived the shrapnel and fear effect of the goblin body parts flinging out underneath you as you bashed into their friends
. Those who dont run away will get killed by you LOL. Thats just a suggestion mind you and sense you cant be critted more fun. Get DR from the Feat ROLL WITH IT from Savage species to lessen the damage.
If I could do that to my DMs monsters and argued that! and if I was able to pull it off I would die laughing, im just to shy to argue that point