Piperboy, the best advice here is to visit Deeside Gliding Club website, and then book some flying - those folks know all about wave and how to use it.
It mentions, by the way, that the height record set there is 38,600 feet....
They offer instruction at quite reasonable rates. In gliders fitted with Oxygen, which is probably a cheaper deal than fitting your Maule with Oxygen! And if your Maule has a towhook you might be able to come to a special arrangement..
I got my diamond height at Deeside, 20,300 feet gain of height above the airfield. If any glider pilots would like to know how I dun it, it involved crossing from one bar to another not at the strongest lift place but at the weakest lift; less sink on the way to the next bar upwind. Magic!