If specing out a new boat, what GPS would you recommend to install.  Do any of the various mfgs (garmin, etc) offer electronic marine charts for inland lakes?  

I have Garmin fish finders and a Lowrance GPS on my boat (the GPS was an after thought).  I can't really give you a reason why, but I'm a little happier with the Lowrance product.  Both however are excellent products.

If you're think you may use a portable or car unit in the future, I'd think about buying a brand that supports all my present and future needs.  It makes database purchases cheaper since they could use a common database and familiar keystrokes or functions between units cuts down on confusion when switching between units.