Radio for model boats?

[mikethepipe]

I'm new to model boats and would appreciate advice on recommended radio transmitters. Looking ahead, I might need 4 or even 6 functions (channels) and the ability to mix functions for operating 2 motors if necessary. (Or is there another way of doing this?) With my R/C aircraft I'm used to using transmitters with model 'memories' - is this useful in boating? I've noticed the JR X756 and Futaba 3VC, but these are rather expensive!
Any ideas/suggestions please?