I've used SF Cremonas with a bunch of amps, ss and tubed. Generally, I'd agree with your instincts toward ss amps (or hybrids with a ss output stage). That said, my ARC VT 130SE worked very nicely. The ARC amps are pretty neutral sounding tube amps, the appropriate models have adequate output, and they aren't bothered by the SF's load. They're also in your price range.
BTW, I assume that you're using the REL with the high level set-up. If you're actively crossing at the line level, you can choose pretty much anything you like.
Marty
BTW, I assume that you're using the REL with the high level set-up. If you're actively crossing at the line level, you can choose pretty much anything you like.
Marty