I ran an 8w7 with a variety of amps...from the sub channel of an HD900/5, an HD750/1, and even an HD1200/1.
The sub sounded very good with 500...it sounded fking great with 750....it sounded amazing with 1200 BUT it got real stinky after about 15 minutes (definitely pushing the thermal limits above 1krms).
I would suggest the RD1000...the 8w7 will chew up 800rms and love it!
Actually I DO NOT suggest either of the RD amps...they both have fixed subsonic filters @30hz...this (in my opinion) is a BAD thing....you need an amp with a VARIABLE subsonic filter (if going ported). If running the 8w7 sealed then the SS filter is irrelevant.
If you are going ported then definitely go with the 500/1 Slash series...VERY good signal processing tools on that amp and they are very under-rated.
JL 8w7 in 1cube tuned to 32hz [Grey - 30hz ss filter 24db] [blue - 21hz ss filter 24db]
The 9 hertz difference in SS setting provides the 8w7 the ability to utilize ALL of is linear excursion where the 30hz filter basically cuts off it's balls. At 20hz the system set at 21hz SS is 9db louder, at 30hz it's 4db louder, and at 40hz it's 2db louder...and all while staying within linear x-max.
People don't seem to pay much attention to what a correctly set SS can do for a ported sub.