Lowrance Sonar advice sought

Question is ................which one to buy?

http://www.lowrance.com/Marine/default.asp

This is there list of Fish finders.

I just bought a new 17 ft Lund "Fisherman" boat.
I am a sportsfisherman and fish on inland waters in Canada not exceeding
800 ft of Depth for Northern Pike, Walleye, and Lake Trout. I used to own
the 1993 model Lowrance LMS350A and let it go when I sold my last boat.
I am thinking about buying the X135 Lowrance. I won't be using any built in
GPS as I already have a hand held GPS.Can anyone comment on any of these
Lowrance products?

Thanks in advance for any suggestions...RegardsJim