Options for Stax SR-L700?

I recently got a pair of Stax SR-L700 headphones (um, "earspeakers") from a seller here; unfortunately, I missed out on the amp he was selling in a separate auction.

I'd really like to stay under $1000, so my budget doesn't quite let me go for the SRM-007tII. The SRM-353X is really the only thing in the current lineup in that range. I'd prefer tubes, but the new tube options, like the SRM-007tll or the Woo Audio GES, are all rather above that number, as are other non-Stax options like Mjölnir Audio or HeadAmp's own amp. The options on eBay seem limited or not necessarily trustworthy. There's an SRM-1 Mark II for sale here; is that capable of driving the SR-L700s well? I'm not clear how an amp from 1989 holds up nowadays.

If there are places I should be looking, or things that I should be looking at, I'd love to hear about them! I'm facing the prospect of these headphones arriving and my not being able to listen to them, and that makes me sad!