Well, I had some ideas, kinda cheesy to have a party like this but...
A cleric 4/crusader 1/RKV 7/??? could work both as the "heavy dude" and the healer. In fact, you could probably do some awesome lockdown with it. I'd go as far as to say you should try to squeeze some huge single target damage in there too, for some four-on-one boss battles.
For the one who manages traps, you could probably go factotum 5/chameleon 10. That'd be awesomely strong and versatile too.
Now that we are free from the requirements with two very strong party members already, let's complement it.
Someone who kills stuff fast. I'd say something along the lines of swordsage/telflammar shadowlord, tough I'm not too well versed on this kind of build. Still, if you can manage "kill 3 guys in one turn, run back home and prepare for the next onslaught" kind of thing, that'd be exactly what to look for. As they say, it doesn't matter if you do a hundred thousand damage in a charge if you'll just kill one guy. In practice, there usually is more than one. Also, I love the flavor of blinking around in the battlefield bringing death to those close to his destination. You could probably get some more power in there, but yeah. I assume this would be the best choice for a "striker" here, but usually I'm more in the ubercharger part of the CO
And lastly we need a god. This build uses early entry and stuff, so bear with me
If no flaws are allowed, at level 1 chose human and extend spell, sanctum spell, spell focus(abjuration) and go wizard 2. Then get a level in master specialist and the iron will feat. Know where we are headed? Oh yeah, incantatrix 4. While there, greater spell focus(abjuration) as your 6th level feat, persist spell as your first metamagic feat. Now, just go in initiate of the sevenfold veil and make them all cry. Problem is, you can't really go iotsv before level 9. You are level 7, so what to do with those two levels? Well, you could get two more of master specialist to gain a free feat, instead of using your 6h level feat for greater spell focus, or just using something else. Or you could ditch iotsv altogether, but meh. I like that class too
It should end up as Wizard 2/Master Specialist 1/Incantatrix 4/??? 2/initiate of the sevenfold veil 5
This party should just breeze through mostly any content made for a regular party, I'd say. So it might be a bit too much.