Sound quality impact - preamp vs power amp?

The amplifier is far more important than the preamp even if it has a phono stage. Amplifiers and how they are matched to the loudspeakers can make or break a system. See what happens when you put an 8 watt SET amp with Wilson's. Some speakers require a lot of power. Without it they are lifeless. Makes no difference what preamp you are using. 

Sounds like a hypothetical question to induce responses. If the OP was serious, he'd simply consider an integrated amplifier within his remaining budget. Would you put an entry-level cartridge on a high-end turntable? Which is more important when all things are important? 

Speaker and amp tech may not change so often as the preamp/streamer/DAC   So my view is nail those down first.  Make sure you can return whatever you get. Happy hunting. 

This is getting old both are very important.HELLO!!

Everything matters