You have alot of very high quality stuff and powerful amps that need alot of juice. In that vein, you're probably smart to have tried the RGPC and 20 amp BPT stuff for all your equipment versus the more current limiting types of power conditioners/filters. If you liked the RGPC on video, then I, frankly, would pickup a used RGPC 400s for around $400 and just plug your TV into it.
I agree that the RGPC has a more pronounced imrovement on video. In fact, at CES, many of the HT and TV vendors were using it in their setups. For audio though, I don't think you're going to find much better than the BPT stuff, especially for the $$$.
You could look into upgrading your BPT to the 3.5, but I would run it past Chris at BPT first for what potential improvements you could expect.
Other than BPT, I'd recommend installing a 240 volt line and use Richard Gray's new Substation. I would put the Substation in the attic and have all the outlets in your room fed by it if possible. Combined with a few RGPCs, that would be a pretty impressive (albeit expensive) power conditioning solution.
You could also look into new Running Springs Audio conditioner, which has gotten excellent buzz. Also, I recently heard through the grapevine of a "revolutionary" new conditioner that is expected to come out in October, and it supposedly outperformed the $10k Burmeister and Accuphase products.
Again though, I think you may already be at the point of diminishing returns .