blk85vette

I have the round coil packs on modded Z06 - 730 RWHP supercharged. Stubbling past half throttle HP tuners showing a dip in spark and I changed plugs wires a few months ago so thinking its a coil pack but not sure which ones to get and the ones on the car are round and have no part number. the numbers on dont come up on any site so which brand works best? and does anyone have part number for the round coils.