I think an Eagle EGC series part would also work. You need to call lowrance as I think these modules are now obsolete. There is a global map 1000 with EGC-1 module on ebay for 155.00 bidding is at 50.00 now.
shootnhunt.com has a 12W and there was a brand new LCG-12 here http://iboats.com/cgi-bin/marine_cla....cgi?id=122150
they aren't cheap. Might do some more searches, posts on "bass fishing homepage" and "bassboatcentral" websites. Google will get you there.