I have the Actron scanner to use with out (It's funny that I still say "our" when I haven't driven it in months) '95 C280. I bought it for one reason: last time I went to a shop to have the codes read, the tech used an Actron, so I knew that it would work.

Pep Boys has the scanner on sale for $99 right now.
http://pepboys.crossmediaservices.com/pepboys/listing_detail.asp?listingid=-2098112390&storeid=2315197&offerid=

Mercedes Benz does have some things that can't be checked via the OBDII connection. The one that springs to mind is the SRS (airbag, seatbelt tensioner, etc) system. That one will require a VERY expensive computer to diagnose (and reset the light if it comes on). The check engine light (and associated problems) will be able to be read and reset with this tool.

If you really want CAN support, I'd say get a cheaper scanner for now. Then once the CAN system is really firmed up and in use, get a CAN compatible scanner. You certainly won't need that feature for your 96 Mercedes.

-Tad