MSD BTM = MSD boost timing master. it retards timing per pound of boost according to a preset setting which is controlled by a knob, i think its adjustable 0-3 degress per lb. i wouldnt waste your money on this as all ROM editors can adjust timing to your specific motor needs and do not require a piggybakc like the MSD BTM

cam gears are not necessary but wont hurt. if you cant install them yourself and arent getting them for cheap i do not think theyre worth it, use the money elsewhere.

fuel pressure reg also is not necessary. i wouldnt waste your money on a pos B&M. if youre getting an adjustable regulator get a quality one or just leave the stock one on there as it will work perfectly fine.

also you can use either a socketed P75 or P06, doesnt matter since there will be a custom program on it anyway.

other than that the above advice is fine