I bought a Garmin ECHOMAP™ UHD2 5" with Navionics a while back
I haven't used it all that much since I don't get out on my boat often, but it's a nice piece of gear
I bought it on ebay and was sadly not able to get the preloaded maps to register in my Active Captain APP. Turns out they are not transferable...so If I ever want full function, I'd have to buy a recurring subscription.
Wish I'd have bought it new instead, but it's really not the end of the world. Eventually though the charts will become less and less useful.
I also would have liked a larger unit but I'm limited in space for it...and also the cheaper price for small is good.
If I ever buy a new one, my plan is to make a new and nonpersonal generic gmail address to register it to, that way if I ever want to sell the unit or the boat, the whole thing can be transferred to the new owner. I haven't totally thought that through but I think that might work.
Your problem would be which database to get. The inland vs coastal database. I'm not sure how far offshore the inland database goes...and I don't think that the coastal one would have your lakes