We used a liner from Bend Tarp & Liner for three reasons (1) it is a local company and we didn't have to pay shipping(I believe they ship around the world though); (2) with their heavier duty liner we didn't have to have a perfect underlayment for them to warrant against puncture (as opposed to water getting around the edge of the liner - that was my risk), which was important because of all of the rocks (we did try to remove some of the sharpest looking ones); and (3) They warranted the uncovered liner against U/V damage so long as it was under at least 6 inches of water (we weren't able to cover the liner because of slopes). I don't know if the last two features are unique to their product - we didn't shop too hard for other options given BT&L was local.
I believe the price was around $.42/ft for the liner. Install was additional.
I liked them and their product seems very tough and durable. Come to think of it, I should get my hands on an extra copy of PB magazine, give it to them and suggest they think about advertising.
When I spoke to the folks there, they had seen the partial lining attemtped before, and they told me they had seen some successes, but also some failures.
