I'd say then, just convert the front to 99+ SN-95 brakes with 94-95 spindles. You'll have the largest selection of wheels available to you that way, and the 99+ PBR calipers are supposed to stop really well. I believe with this setup you can still fit 15" drag wheels without modifying anything, but don't quote me on that. This is the direction most guys take when converting to 5 lug. Replacement rotors and pads are really cheap, and if you ever feel the itch to upgrade to Cobra stuff, you can reuse the spindles and hubs.
You could go with Cobra front rotors and calipers, as it only costs a little more to go that way (if you know where to shop), but if you are looking to avoid switching the MC and BB, Cobra brakes might be a bit much for the stock stuff. Cobra fronts are also going to completely ruin your ability to run 15" skinnies (the rotors are 13" by themselves). That and Cobra fronts with drum rears is a horrible mismatch.