I am trying to buy my first tube amplifier. Budget is about $2500-3500. I am not very good at doing electrical work myself and do not intend to restore/repair/update the equipment myself. No time for another hobby.No good for tube amp. At least you need to know when to replace tubes and on some units you need to know how to bias (usually instructions are in the manuals or available to download online).
The lowest maintenance required tube amps are Quicksilver (not done in China yet for good vibes:)) and it's the BEST starter amp period. Depending on speaker of your choice, you can choose within your budget the right one. I'm fan of M60 that can accommodate different power tubes such as KT90, 6550, KT66 etc, but there's a newer version and perhaps you've mentioned that one....
Spend little to no attention on type of amp operation weather it's push-pull or single-ended or sepp or SET. All you need to know is your speakers, your room and power speakers require.