H Bbgun, I am going to pickup on your statement, "simple stereo recording seems attractive" Bloody right!

If you are all good musicians you should be able to deliver a balanced sound into the room* and that without amplification. A pair of 90dgr "Co-Incident" small diaphragm capacitor mics should give you a very fair representation of the trio's sound. "They" did it this way for YEARS!
This assume the drums is not a full rock kit and you don't feed the drummer raw, red meat?

If perchance you are in UK drop me a PM.

*If at all possible find a bigger room. School premises, church rooms, pubs out of licencing hours. Not as though you will be making a huge noise or anything "satanic"? But, no matter the size of room, stay with CO-I.

Should have said. Beware the USB mixer market. Later gear with 24 bit converters is fine but there is still a lot of the 1st Gen, noisy 16bit kit about.

Dave.