Your post made my brain hurt. I know this isn't what you wanted to hear but, "I'm trying to spend as little money as possible" is key word, "I can't afford a BMW". Sorry to burst your bubble. After buying an E46, plan on spending $2k right off the bat to address any problems it has as well as get it up to date on maintenance. These cars will leave you high and dry quickly if you have a limited budget.
To answer one of your questions, stay away from 99-00's if you can. Subframe issue as well as a reverse issue in the autos seems to be more prominent in those years.
1995 325i 5mt ArcticGrey/Dove - SOLD
2004 330ci ZHP 6MT SilberGrau/Black - SOLD
2001 330i M-Sport 5MT StaulGrau/Grey - SOLD
1992 Accord LX Sedan 275k miles all original - DAILY
2002 Chevy Suburban LT Autoride - TOY HAULER
2005 GMC Sierra 2500HD SLT - RACE TRUCK!