Byzandula, I have been using a 12x8 APC mostly for speed runs, and a 13x6 APC for sport flying. If you want to go vertical I would try a 13x5. The Tower gets it best power by revving up. Mine will go vertical till I cant see it.

My Hanger:
GP Ultrasport 60 w/ OS 90 FS Surpass ll Pumper, Mistress Pattern Plane w/ YS 60 RE on Tuned Pipe, VectorFlight 66in Extra w/ Magnum 91 xls
GP Viper 428 pylon racer with Nelson 40, GP Shoestring w/ Tower .75, 70in. Sig Citabria W/ OS .70 Surpass on Sea Commander Floats
Kangke SK-50 w/Magnum .52 xls Scratch built 40 in. Shoestring w/ Aveox 010 Brushless motor, Crazy Sparrow w/ Astro 05 Brushless

About 20 gliders including 4-meter ASW-20, Kit Built Bird of Time, 3-meter DG 600, Swift 2-meter scale Aerobatic, Sig Ninja, Hobie Hawk, old Bob
Martin Coyote, Paragon thermal duration, Ben Buckle 60 in. Scorpion Old Timer w/ OS 40 Four Stroke

Glaser Dirks DG- 202 17-meter : Flaps, water bags, oxygen, computer/nav. 48:1 glide ratio 2000 hrs PIC