I'm looking to get a new electronics unit for my boat (14' Lund). I would really like GPS, but is it worth the cost? I typically fish lakes about 1000 acres. Would it be more worth it go with 2 cheap sonar only units, one bow and one stern? I guess my main question is, what setup do you have, and if you had it to do all over again, what would you change. My budget is about 400 bucks. Thanks.

Sonar are you eyes underwater and can tell you a lot about what is happening down there. With you budget of $400 I would get 1 good sonar. Cheap sonars are exactly that, cheap. They will last a couple of years and they you throw them away and get a new one. If you really want them to be fishing tools, get a good one. If you just want depth and temp then save a few bucks and go cheap. I have gps on the console and front end and probably find I do most of my marking at the front but use the console gps to get back to those spots quickly. I just recently got a Humminbird 997 side imaging unit and that thing is absolutely amazing, but quite expensive. For you budget get the most pixels and power you can afford.  If you want gps try a Humminbird 580 with mapping and get yourself and extra mount and transducer so you can move it from the console to the front.  Unit runs $360 + $30 mount and $50 for extra transducer.  

You can do what I did. I bought an Eagle GPS/Sonar unit. It's made by lowrance but has a little less resolution screen on the same size screen (color) and lacks the networking capability of the Lowrance unit. It was around $400 on sale at BPS and then I got a Navionics chip for it.

I mounted it to the side of the console in my boat with a RAM mount. When I get up to fish I just loosen it up and I can spin it around so I can see it from the bow if I want. I have another cheap depthfinder at the bow but sometimes I want to see the big screen/color or the GPS.

Just something to think about.

You can also check places like Cabelas now has last year's Lowrance models on sale for a lot less than they were new last year....

I would go with 2 Fishmark 320's.  By far the best for the money.  I did a lot of research before I got mine, and all roads lead to it.  Sure, you can get better, but the quality/resolution to money ratio is the best tradeoff here.  

Try one of these

http://www.walmart.com/catalog/product.do?product_id=5141291

cabela's has them too.

http://www.cabelas.com/link-12/pod/0023861.shtml

With a budget of $400 I'd go with a pair of Fishmark 480's. They're about $200 each.  Yes, they're black and white units but frankly, color units don't do anything other than add color to the screen, they're no better than the B & W units.  If you want a GPS, you could get yourself a Garmin Etrex later for a little over $100.