My experience is that people want to play Black Spiral Dancers / Baali / Nephandi / Marauders because they're cool and different and Evil Campaigns Are Fun (tm).
I tend to run fairly system-light games, and would be happy for players to go with a concept that works for them rather than a set of game mechanics. Depending on what kind of players I get, the 'uneasy alliance' will shift.
A group of Order of Reason mages (aka Technocrats) is going to be easier to meld together than a Hermetic mage, a Toreador Vampire, and a Werewolf. Rest assured that I'll come up with something
that needs to be done. This won't, however, be the D&D cliche of 'You all meet down the local pub'. I want the alliance to be uneasy.
Here are some useful links:Sorcerers CrusadeThe Dark Ages meta-setting
If you want to play something that's not covered (for example, a Vampire in the SorCru setting), then we can probably work something out.
In case people want to be a bit different - and I'm looking at you Sephora - the following 'races' are allowed: Vampire, Mage, Woof, Demon
(it'll take a bit of tweaking but I'd use the Demon: the Fallen rules). I'd really rather not involve inquisitors, changelings, or wraiths.