However, in your case I don't really see a better option than you
tried
(but i also lack any experience with laser cutting). Hope Mo and Paul
can get you more useful answers, since they are more suted to talk about
logo usage.
I can't speak to the logo usage/legal part of things, but a couple
engineering buddies with more laser experience than I've got concur: if
you can etch the "infinity" part, all problems are solved. (I've yet to
find a laser cutter that can't engrave, and they seem to be making
similar assumptions.)
http://blog.melchua.com/2009/07/28/how-to-lasercut-a-logo
--Mel