Re: GPS/Fishfinder Combo Recomendations:
I have a Garmin too, a 178c color plotter sounder and I love it, the fish finder is super accurate as is the GPS and being color is really cool and the split screen is great, you can also choose what is diplayed on the screen, I have voltage,speed and time on my split screen.
Mine and Firemans are previous generation but the new ones are pretty much the same, I think the new model is like a 420.
What I like most about it is you don't need to take a college coarse on how to use it, the interface is really easy and it will tell you everything, total hours, time moving time sitting, top speed, average speed ect ect.
In the end it is your money, compare everything and see what works best for you.
I got you beat on getting a deal Fireman, I got mine through work, new in the box for $50, I am pretty shameless when it comes to getting a deal, I found this in a cabinet back in R&D and knew it was a couple years old, they can't put it on a new boat so I got the deal.
Found a 55lb Motorguide wireless trolling motor upstairs too, the thing had so much dust on it you could hardly tell what it was, turns out it was 3 years old and had never been on a boat, I got that for $100, I really like my job.