I'm the owner of the rare 17' Parker CC - love the boat for the type use I have for it (pleasure & fishing) I have an older hummingbird fish finder which works very well but have decided now I want to add GPS. I have a small console so space is limited. Any suggestions on a good either just GPS or combo unit? I've been looking at the Garmin 478 which is on sale at a lot of sites now at a good price, any comments on this unit? I could still keep the fishfinder and just add GPS if needed. Any comments on smaller GPS units is appreciated, I could go up to the 5" screen size and still have some room. Thanks for any input!!!!