Water tank gauge recommendations?

[Canibul]

I'm presently working on patching up tank #3 of our four tank, 200 gallon fresh water holding system. These are custom made stainless tanks developing problems, but I'm trying to get a few more years out of them before replacing with plastic.

The water level gauge sensors on these tanks are completely eaten away. I'm looking for replacements, and see that there are some options to the Moeller universal tank float things that were in there.

I've been looking at these:
http://www.defender.com/product.jsp?...307&id=1638065

http://www.wemausa.com/sensors/level...l#.VVc6eflViko

Can anyone with these sensors in their boat recommend them, or some better technology to a moving float arm and exposed potentiometer? I need two sensors, with a tank depth of 22". I think plastic would be a better choice for an in-tank sensor housing than adding another grade of stainless, for starters.