Bill,
I originally had a small block 302 in my Cobra and I was running my front coil overs w/ 350 pound springs. They worked great. I also started out with the 9" brakes and I quickly threw them away. Go immediatey with the 11" brakes or bigger. You will need and want all the brake you can afford.
I have a complete set of 11" brakes (rotors, calipers, bearings, mounting brackets, brand new set of pads plus with a set of Porterfield Race pads ($90 per set) with an extra set of new metallic pads I will sell you for $150.00 complete, if you liike. They have very little time on them (only used by a little old man on warm Saturday and sunday drives)
Good luck and feel free to come to this site for any of your questions.
Clois