They CAN be male, yeah, but they're typically sterile if they're male. It would be super interesting to have a male tortie though, and he could struggle with those feelings later on of realizing he's infertile and can't have kits. Still though, it's very rare, but they can, again rarely, but fertile.
That sounds perfect, honestly! Calico, tortie, red tabby, gray tabby, and another tortie/calico! Which one did you want to play? We can pick ours first, and leave the other three up for grabs.