After much painful internal debate, I have decided to rebuild a 4l80e for my conversion. I wish that I could afford one from one of our fine sponsors here, but that is unfortunately not the case at this point in time.
I've noticed that most builders appear to use the Alto Red Eagle power-pack kits, which allow more (albeit, thinner) steels and clutches in the packs. I spoke to a local builder who says that he prefers to use the "high energy" clutches and steels instead. In his experience, the thinner clutches/steels are more prone to warpage under high-heat.
Also, I have about $2200.00 to spend on parts for this build, so if anyone has any leads as to a "one-stop-shopping" supplier for the needed parts, I would appreciate it I already have a new 3400 multi-disc converter from circle D that cost a pretty penny, so I'll be using that with this trans. The goal is for the trans to live a long life at 800hp power levels....maybe eventually more once my 6.0 stroker is done.