Fuel Tank - Plastic?

[65Bowrider]

I'm working on a 66 Bowrider, has a SS tank that weighs 110 pounds!! (approx 29gals). I'd like to lighten it up.

I found a place that could make up an aluminum tank, but cost would be almost $400 with shipping. Found a plastic fuel tank for below deck that was less than $200 with shipping and weighs only about 25 pounds.

Anybody have experience or know about plastic fuel tanks?
Any info would be appreciated!

Then, what to do with the SS tank.....