Hmm. Voting for 'both', too. Can I play a Mortal (Possibly with Numina) or Ghoul (assuming a vampire would want one), though? Or should I be planning to be a vampire, too? I'd like to know what I'm doing so I can let my ideas for a character percolate before I make him.
Numina is a problem. My reasons for that are pretty simple: if you start as a Mortal with Numina you'll either need to remain a pure Mortal to retain access to the Numina (the static nature of Ghouldom and the Embrace sever a Psychic/Sorcerer's ability to recharge/access mana) that you've sunk freebies and XP into or you'll become a Ghoul (and eventually a Lick) and be way behind on the power curve, thus requiring more work on my part to design encounters that you can surivive while retaining the challenge factor for the people who are 'ahead' of you in terms of power.
Now, if you want to play a Ghoul or, if you absolutely insist on playing a Psychic/Sorcerer while understanding that your character's death ceases to be a matter of 'if' and becomes 'when' we can talk more in FPMs.
While we're on the topic (we're really not, but it needs to be addressed given the nature of this site) on Vampiric sexuality...
Vampires as a whole do not engage in sexual activity. Why? Because of diminishing returns. It costs Vitae to make the body appear to be human (Specifically, 8*- [character's Humanity rating] in Blood Points. For example, Joe the Brujah has a Humanity of 5 (he's been a bad boy!). He wants to have teh hawt sexxorz with a Mortal. To do so, he has to spend 3 Blood Points to appear human enough to get a hard on.), and even with that in mind, some Licks absolutely cannot pass themselves off as 'human'. If your character is on a Path other than Humanity or Feral Heart you absolutely cannot spend Vitae to appear Human.
With that in mind, compelling reasons such as feeding (via seduction, to maintain the Masquerade- if you're Anarch or Camarilla), rewarding a Ghoul, or things of that nature are valid reasons to spend the BP needed to shag. "I like sex!" is not, however, given that the physiological imperative to have sex has been replaced on all levels by the psychological addiction to Vitae. Vampires replace sex with feeding, and crave the Kiss.
* Thanks Andy, for calling me on my error. I had 10-, he double checked for me, and it's 8.