Thanks, everyone.
I found this page http://rheimbuch.posterous.com/rvm-and-textmate which explains how to setup the symlink and the TM_RUBY variable, It works pretty nicely.
On the FAQ for rvm ( http://rvm.beginrescueend.com/faq/ ), I also found where they talk about how to set it up, and go around modifying files. I did the modifications, but if it got me something better than that first link, I couldn't tell, so I took them back out (they made me a little nervous).
Anyway, that first link seems to have resolved the last of my issues, so I appreciate the help.
-Josh