I would think with those specs and assuming a smooth impedance curve that 60 tube watts would be plenty of power to drive them as loud as I would ever want to hear them. That of course opens up a much wider selection of choices - though I could hardly recommend a better value with great sound than the Music Reference RM9MKII previously mentioned, or the Quicksilver V4s if you want a little, tiny bit more margin of error over 60 watts on ultimate volume. I run my Merlin VSMs (89db, smooth 8ohm) with 30 watts integrated tube - no volume issues.
Tube amps vs solid state for large speakers
I am looking to experiment with a tube amp and currently use a tube phono-pre with a solid state amp. Problem is I am concerned that I wont be able to get enough power to drive my speakers with tubes, which are A/D/S L-1590 @ 8 ohm rated to 400W. Any thoughts out there? Also, what tube amps would you recommend to try out...under 2K used.