I've talked with Zoops, March Performance, Vintage Air, and a couple of other people. I think the only real options are the Bowers bracket or making your own like love-my-V8-280Z did. All the other kits are very expensive and are either too wide or too tall. The stock alternator is mounted as close as it can possibly fit on the passengers side, and in order to move it to the driver's side it needs to be pushed up or out (the stock location fits in front of the head, which it cannot do on the drivers side because the driver's side head is farther forward than the passenger's side head). So...that leaves dealing with running the lines around the back of the engine bay before going through the firewall. I just got an email from 240playtoy, and he's thinking maybe the lines could be routed along the frame rail to the front and then across and back to the firewall. That sounds like a pretty good solution, thanks Andrew.
One of the problems for me was that the Bowers bracket is made for the stock LT1 compressor and not the Sanden 508. Vintage Air ensured me the stock GM unit will work, and they even sell adapters that go on the back of the compressor that will allow you to install the Vintage lines. I don't have the stock compressor, but that issue was solved when I talked to Joe (Bowers) and he offered me a good used one for $50.
So anyway, the compressor and bracket kit should ship out tomorrow and soon the real work will start.