Check out the Balanced Audio Technology VK-55.
If your S5e's are anything close to my 1/2e's then you're going to need a bit more power based on the size of your listening room and your listening position. I was using a 50 watt tube amp that did a nice job with my speakers, but it wasn't until I went over the 100 watt threshold that I could really appreciate them. I own a Music Reference RM-9 100 watt (tested close to 120 watts on Roger Modjeski's bench when I took it over to have it upgraded to a MkII) amp and TRL D-225 225 watt solid state amp and both work nicely with my speakers. The Music Reference is below your price range used and worth checking out.
There is more to this than just power output.You will probably need a higher damping factor which is almost beyond valve amps.I understand though that Supratek is developing a KT88 amp with a much higher damping factor[maybe as high as 200].It might pay to wait and see what comes from this.
I have owned and loved Spendor speakers but they are not easy to drive.