Cammie, remember that you get what you pay for! All pond liner is not the same. The things you want when buying pond liner is a Fish Safe and UV Stable liner with a LONG Warrantee.
Here are a few examples:
Tetra Brand- Available in 20mil and 32mil PVC: Cheap to buy but only warranted for 5 years and only against manufacturer defects. Also, its pliability is temperature sensitive. The colder it gets the more stiff the liner is. When temps get below 40 it gets down right brittle. Should it develop a leak or puncture it is the most difficult liner to repair.
Aquascape Brand- Manufactured by Carlisle Co. 45mil Rubber ROOFING material. Made from recycled rubber and not Guaranteed fish safe and not guaranteed UV Stable. Recycled sounds like a great thing but you do not know what was used in the recycled process. 20 year warrantee but only against 'Manufacturer Defects' and is 'recommended that you completely cover liner to prevent UV breakdown'
Pond King Brand- Manufactured in China and is a "nominal 45 mil" which means it has an average thickness of 45mil. Some spots have been measured at 18mil and others at 60mil. Has a stated warantee of 20 years against 'Manufacturer Defects' and does not state to be UV Stable.
Firestone PondGard Brand- 45 mil 100% Virgin Rubber with 20 year warrantee on Everything bu punctures! Should this liner crack, split, shrink or degrade from UV it is replace. If it develops a puncture it is easilyrepaired with a $15.00 patch kit. This liner is heat tested at 190+ and cold tested at -60 and is plyable at this entire range. In the 20 years we have been selling this product, we have never seen a defect or had a warrantee claim.
On your second question about a rock quarry, please realize that most quarries in the eastern part of NC are producing a granite type stone that is high in Phosphates and will grow the best crop of hair algae you have seen. Rip Rap is the worst stone to use in a water feature. The stone to use is a fieldstone such as from Tennessee, Virginia or Pennsylvania.