Steve, my answer may be a little different to some of the above.

First find a good MIDI from the Web. Play it back through your sound card, adjust for echo and reverb if your soundcard/software allows it. (if your soundcard sounds crappy then download Wingroove). You already know that you can adjust the tempo and key and/or change the instrument settings to suit your own ear. Because all souncards do a lousy job of rhythm guitar turn that channel off or change to another instrument. Record to two of your four tracks on your faithful analog recorder.

Record your voice and guitar on the two remaining audio tracks. You can then do a digital stereo recording on your PC and add further effects if you like after this event.

Wingroove is about $20. This plus the cost of an audio lead should give you quite reasonable results for a very small outlay.

If you can't find a suitable MIDI then I can probably direct you to a free package that does most of the work for you. You enter the chords and the style - it's fun and the price is right, but it's better for pop, classical, jazz and country styles.

Hope that this helps. Regards, John