stop being a girl and choose!!!
(unless you are a girl, then I'm really sorry)
and ask MisterX about your op-amp choices and ask him what he thinks is the best combo for your rig.
and come on man, theres so much info in this forum about the pimenta and the xp, its not hard to make a decision. Theyre both good amps and i dont think you'll be dissatisfied with whichever you choose since this is your first amp.