If you decide to get the Thiels, might want to research Luxman R117 (don't know how powerful an amp the Thiel 0.5 needs, but if they are not as demanding as their larger brethren, the less power avrs in that series, e. g. R115, might also work). Just be aware that replacement parts are probably rare and expensive, so you would also need to research what type of maintenance is needed to bring a say 20 year old component up to working condition now.
Vandersteen 2ci /2ce series is full-bodied, perhaps a little dark, but eminently musical and easy to drove (I think even 60 watts of clean, neutral solid state would work well - heck one Vandersteen dealer found the AMC CVT3030 to be very synergistic with Vandersteen 2ci - this was in early 90s). Outlaw 1050 AVR could also work well, though my personal preference would be for something with more tube-like liquidity, such as the AMC CVT3030 mentioned above). Another Vandersteen dealer was using Spectral reference amps with the Vandersteen 2ci. IIRC, Sound by Singer also recommended a system of Vandersteen 2ci with Audible Illusions Modulus 3 tube pre-amp and Aragon solid state amp (forgot if it was 2002 or 4004) in NY Mag in 90s. I am guessing that something that is crystal clear, ideally with tube like liquidity, would work well with these speakers (I think something like Quicksilver Audio tube monoblocks might be awesome combo, though well above your stated budget). Even current generation Pioneer AVR might work well, though other options mentioned might be better in an absolute sense.