Fishfinders under $100

I'm comparing the Eagle Cuda 300/Lowrance X-4 vs the Garmin Echo 100.

The X-4 & the Cuda 300 are identical. (I think) The Garmin looks similar.

Is there another I am missing?

Piranhamax?

What is the opinion here of the older Garmin models. ( 80, 90 etc)

Links to models:

http://www.cabelas.com/product/Boating/Boating-Electronics/Sonars|/pc/104794380/c/104707080/sc/104588280/Lowrance-X-4-Sonar/1158221.uts?destination=%2Fcatalog%2Fbrowse%2Fboating-boating-electronics-sonars%2F_%2FN-1100517%2B10000050%2FNe-10000050%2FNs-CATEGORY_SEQ_104588280%3FWTz_l%3DSBC%253Bcat104794380%253Bcat104707080%26WTz_st%3DGuidedNav%26WTz_stype%3DGNU&WTz_l=SBC%3Bcat104794380%3Bcat104707080%3Bcat104588280
Holy Crap that was long!
http://www.amazon.com/Garmin-Single-Fishfinder-Trolling-Transducer/dp/B004FKP1XM/ref=sr_1_1?ie=UTF8&s=electronics&qid=1302455318&sr=8-1
That was slightly shorter.
http://www.amazon.com/Humminbird-PiranhaMAX-4-Inch-Waterproof-Fishfinder/dp/B001DTWW62/ref=sr_1_3?s=electronics&ie=UTF8&qid=1302455416&sr=1-3

Single beam vs. Dual beam transducer?


I'm looking at powering it with a sealed gel cell 12v. (I've got the room)

It will be mostly be used in fresh water with an occasional salt water trip in semi-protected waters.

Any and all info will be appreciated.

A.J.

i ve been happy with the 300 and x4. If you can afford the $'s color is great for FW. I see much more with my color version. AND it uses the same connections as the 300 and X4