If I had allot of room and more than 1 tall tree, I'd put up a Full Wave Loop. As large and as high as I could. Put a 4:1 balun at the feedpoint, feed that with coax. You'll need a tuner. My buddy KA9NRT has a loop cut for 40M and that thing has always amazed me. Check it out ---->
http://n1su.com/loop.html
I've been seriously contemplating a 20M Delta loop here. My yard is big enough for a fullwave loop on 80M but I don't have any supports :( (Only 1 tall tree).
I have a homebrew Sound Card Interface around here somewhere...... If I can find it, you can have it.