Heres a list:
Engine
Tranny
Starter
Alternator
Distributor
Ecu
90-93 Integra axles
90-93 Integra intermediate shaft (make sure its off a manual, there is difference)
90-93 Integra rear trans mount bracket
90-93 Integra upper radiator hose
90-93 Integra throttle cable
Shift linkage, you can use a 90-93 integra and your stock one, you got to cut and weld it or you can just buy a B series coversion one and save the hassle
B series mount kit
Smash in your torque mount in front of motor on cross member
Bang in your firewall on driver side where the alternator goes in

If you stay LS, you dont have to rewire anything as long as your already MPFI. Thats the bonus of staying straight LS

Now onto the LS/Vtec part of your question:
Golden eagle sells everything you need to do a LS/Vtec conversion. As for 300hp I hope you plan on boosting!! Cause your not going to see those numbers staying n/a. Also simple bolts ons are not going to gain you lots of power, I dont care what your butt dyno tells you.

I have a LS powered crx, so if you need any more advice just ask.