If you are upgrading your radar-COLOR! Water is blue, blue is water, no chance of mistaking the shadow of a sand bar for water!
GPS/Plotter- Color is nice. On some units makes it easier to pick out known objects. If you do a lot of fishing at night, make sure the unit has a bright/dim adjustment that lets you turn it down real low. Stare at a fairly bright display for a few moments than try to look into the dark of night, it is tough! Most color units allow you to change the background to something (amber or black) that doesn't really screw up your night vision as much (my experience).
On fish finders/sounders I think color allows you to more easily tell the differences between weed, small bait schools, thermoclines, real game fish , etc. All comes with experience, though!
LCD/CRT- Best resolution is CRT. The LCD technology has closed the gap some what. It may come down to space limitations- the LCD's are thinner. Whatever, make sure that it is day light viewable!! Bring your favorite sunglasses (especially if polarized) and try viewing the screen with them on. There is nothing more annoying than constantly peering over the top of your glasses when you are trying to find fish or see where you are!
Excellent choices. I was going to get the Lowrance X-16 Plotter Sounder, until I saw the Garmin 2010c which I purchased. I decided to get the Garmin as my primaryGPS/Plotter and use the FURUNO NAVNET Gps as my backup. I'm happy with the integrated FURUNO sounder. If I had the space, and went completely for stand alone units, I would have chosen the Lowrance as a sounder.
The 2 units you are looking at will definitely be under your budget. You'll have lots left for beer! (LOL)