The first question you have to ask yourself is, "Do I want Side Imaging/Down Imaging at the bow?"

If so, then you'll need a 798, 898, 998, or 1197 up there, and you'll have to rig an SI transducer on your trolling motor.

If not, then you're looking at a 788, 858, 958, or 1157, and you can use the US2 in your MinnKota.

The second question you have to ask yourself is, "How large of a screen do I want/need?"

I ran a 788 at the bow of my boat last year. Great unit, did everything I asked it to do, but I found myself wanting a larger screen. I'm replacing it with an 858 this year.

Don't forget the current retail promotion for 858s, 958s, and 1157s bought during most of 2010: free RAM mount and free Weathersense accessory (a very lucrative offer, given the cost of most RAM mounts!)

Another alternative is to try to find a closeout 917 for the bow, but those are getting VERY hard to find as most retailers have been blowing them out for ~ $650.