Depending on if you really want to waste some battery life with the
electronic compass and the barometric altimeter, you could skip the 60CSx
and just get the 60Cx.  Some people like/and or actually use those features,
but I've never personally found them useful.  Once your in motion, the GPS
can tell you exactly which direction is North.  The difference between the
60CSx and the 60Cx is quite a bit of pocket change.

Just a little footnote for the Garmin letter codes.

C=Color screen
S=Special features (such as the electronic compass and barometric
altimeter.)
x=upgradable memory (MicroSD chip)

I have a 2GB MicroSD in my 60Cx and it has all of the street maps of the
contiguous US loaded and it's only using half of the memory stick.  Those
memory sticks that size can be found online for between $10-$15 or so.
Definitely don't buy them at the local store for like $50-$60.

Jake - Team A.I.