Julian your most obvious options are to find a 1ohm mono stable amp or a 2ch bridged @ 4ohm amp. If the Ti's are underrated in there power handling then your looking around 1500rms minimum output at 1 or 4ohm..
Hifonics is not a good choice for those subs, why buy fantastic subs and run them with crap? thats like buying a ferrari and dropping in a 1.8 gremlin motor in it!
haha, lol, i know james, but i was pointing it out to her becasue its one of the more obvious choices, but in one of the threasd she made earlier i told her def not to buy this amp