1) Just to double check with you, Rokugan, you're saying that the Monster Manual, Dungeon Master's Guide, Magic Item Compendium, Spell Compendium, and Unearthed Arcana are disallowed to the players? That's going to make spontaneously casting Summon Nature's Ally and Wild Shaping hard for the Druid since he won't have a book to choose his Animals from. You guys will be left with just the Completes to choose magical equipment from? Harsh.
2) Can you take Prestige Classes out of the Completes?
3) There are a few tricks you could do with a Monk that you might enjoy. They're not completely useless as everyone suggests, but just very scattered on which attributes they need and are horribly puny compared to other classes. ariasderros said it well:
Because, I'll be blunt, making a Monk useful, much less good, in a party with a Wizard, Cleric and Druid would require a lot of CO.
4) Since you mentioned that you'd play a Fighter if they didn't suck, let me suggest Frenzied Berserker. Since you have access to the Complete Champion, you can use the Lion Spiritual Totem which grants you Pounce in place of Fast Movement. How about something like this:
Human
1 Barbarian - Lion Totem (Pounce), Rage 1/day, Illiteracy, [1 Power Attack], [B Cleave]
2 Barbarian - Uncanny Dodge
3 Fighter - [3 Intimidating Rage], [B Destructive Rage]
4 Fighter - Resolute
5 Fighter -
6 Fighter - [6 Improved Bull Rush], [B Shock Trooper]
7 Frenzied Berserker - Frenzy 1/Day, [B Diehard]
Books:
Lion Spiritual Totem ACF (Complete Champion p.46)
Resolute ACF (Complete Champion p.48)
Shock Trooper, Intimidating Rage, Destructive Rage (Complete Warrior feats section)
This would make you a very potent glass cannon with the ability to dish out tons of damage. You could take a -9 penalty to your AC when you charge to deal an extra +14 damage per hit and full attack at the end of it (which Frenzied Berserker gives you an extra strike when you full attack, so that'd be three attacks at weapon damage + STR x 1.5 + 14). You'd be able to Rage and Frenzy at the same time (save for when you know it's the big fight of the day) which grant untyped bonuses to Strength (which your Cleric/Wizard/Druid could buff further) and then use the Resolute Fighter ACF to help ensure you don't attack your allies when the fight's over (the one drawback of the Frenzied Berserker) and ask your allies to bump your Will Saves. At level 5 of the Frenzied Berserker, your Power Attack would deal an extra +33 damage per hit. With your Wizard and Cleric around to buff you, you'll be a flying grim reaper, destroying whatever you see in a single charge.