Birthday Present.....But Unsure What

to get. The fiance gave the a-ok for me to buy a fish finder. I am stuck between the humminbird 535, humminbird piranha 230, and the bottomline fishin buddy 4200 (all portable models). Anybody have any advice or comments on any of these. I have searched the forums and found information on other units but none specifically between these three. I like the feature the piranha has to offer (the smartcast RSS and fixed position transducers).And also does anyone know if the portable 535 has the capability of hooking up the smartcast RSS unit? If yall know of any other similar unit that I didn't list above and like it alot throw it in the mix as well. Any info greatly appreciated and thanks in advance.
-rascal-

Humminbird 535 sounds like a great one. has all the features not sure about the smart cast hooking to it but you can ask hummingbird here http://www.humminbird.com/flashHome.asp?ID=2
i have used humming bird for years they are a good unit and a good company and great turn around if you have to send them in for repairs
but out of the last 20 years i have never had one to break. i have never used a portable unit so cant report on them per model.
~ sticko ~