Getting off the merry-go-round implies being able to make some nice final choices. That requires listening to a bunch of different speaker/amp combinations to find out what gets you 'that feeling.' This means discovering the relationship between Peter_s' question and the amp/speaker combo. For me, it is efficient speakers which go low and tube amps. I would recommend listening to systems where you can to get a feeling of what kind of sound does it for you and THEN asking the same question.
For that price, for jazz/folk/rock/jambands, and an expectation to listen to the same system with no real change for the next 20 years, and a $4k budget, I would choose Altec Model 19 speakers, an integrated tube amp like a Manley Stingray or similar (or some DIY tube amp kits through Bottlehead - you can build them yourself but they also come up on Audiogon from time to time), and your choice of CDP/digital. Personally, I would go for a music server through a 'Buffalo DAC' (twistedpearaudio.com) but that would require some DIY for the DAC. Cables would be your choice or roll-your-own.
For that price, for jazz/folk/rock/jambands, and an expectation to listen to the same system with no real change for the next 20 years, and a $4k budget, I would choose Altec Model 19 speakers, an integrated tube amp like a Manley Stingray or similar (or some DIY tube amp kits through Bottlehead - you can build them yourself but they also come up on Audiogon from time to time), and your choice of CDP/digital. Personally, I would go for a music server through a 'Buffalo DAC' (twistedpearaudio.com) but that would require some DIY for the DAC. Cables would be your choice or roll-your-own.