Definitely agreed on the resonator. A glasspack muffler is actually a pretty good resonator.
Mandrel bent for $60? Are you sure it's not crush bent?
I plan on going this route also... I can't justify $400 or even $600 for a mild steel exhaust when there are plenty of shops that can whip something up in stainless tubing on the cheap, and I can pick what kind of muffler I want.
Also <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'> for magnaflow mufflers... never used one on a 240SX, but they sound awesome on VWs, even the nasty-ass 2.0 8v...