Psychics, sure. You'd all start at level 1 i guess, though i could agree that those who'd play the weaker types would start higher. I have the atlantean book and i can allow the hunter, as well as the plasma whip from it or some other kind of fancy whip. It would be easier to stick to the main book, though, so if you're willing to be a cyber knight, go right ahead. Dark elf leyline walker would perhaps conflict with the CS guy, unless it would be a CS guy who has reasons not to shoot her on sight, which i'd prefer.
If no one would change his mind, the party would look the following:
Ajoxer - Crazy
Guardianangel - CS special forces
Zakharra - Dark elf ley line walker
Siegfried - CS psychic
Muse - Atlantean undead hunter or cyberknight
That would mean a party not needing to fear a couple of Pecos or a stray deamon.
I'm planning to start you in the first phase of the war, way before the sorcerers revenge.
Both CS would be trying to take Zakharra's magic user hostage, Muse's char would likely to just wander in, and the crazy could either be the the ley walker's bodyguard, Muse's companion or merc for CS.
Of course events would require you to join forces, at least temporarily.