Why not take a few rides on your current bike pretending that it's a fixing. Just select one medium gear and leave it there. See if you can get up the hills. Also try to never coast, even going around corners and down hills. That might tell you if you really want a fixie, without the time, expense, and risk.
Oil is good, grease is better.
2007 Peter Mooney w/S&S couplers/Terry Butterfly
1993 Bridgestone MB-3/Avocet O2 Air 40W
1980 Columbus Frame with 1970 Campy parts
1954 Raleigh 3-speed/Brooks B72