1 question at a time, Low to mid 14's is close for bone stock. Mid 13's with mods listed. Your going to need more $$ for a 12s car. If you can slip a clutch good on street tires to minimize wheel-spin, you should be able to run good times. Clutch work and seat time will help.
I was running mid to low 12's with a stock short block with 100K miles on it with a E cam, Holley aluminum heads, and a Performer RPM intake with 3.73's in a full weight GT. The low 12's came on slicks with 5000+ rpm launches and a lot of seat time. So to answer your question... the Trick Flow kit will probably get you there but the GT40's, etc won't.