the roc when new will be a good weight/mold for wind, but once worn wont be to helpful. The weights on discraft discs in the X plastic are stickers so if they werent there I dont know how to tell the weight (other than a good sensitive hanging scale)
I think you should mostly work with the DX lepord for your backhand. Once you can turn it (right throwing rhbh) throwing with just a little hyzer, put alittle bit more hyzer on it and really learn the disc. I origionally threw sidearm, but when I learned my backhand I worked in about this order 150 Lepord, 172 Lepord, 165 Tee Bird, then a 167 Eagle. All these were in DX plastic. (of course i threw other discs between, Crushes, orcs, Champ tee bird, pro firebird, however all to no sucess compared to the DX eagle or teebird)
(I cant tell you to stay away from champ/z completely but its good to learn control with standard plastic)
From there, I bet you could give that wildcat an aswome huck (I would say you probably could throw it pretty well after learning the Lepord)
throwing sidearm although an overstable disc is easier to throw, especially accurately, if you learn to throw a DX teebird or another neutral driver well, you will develop a much better sidearm than if you just learn to huck overstable discs.
Good luck with the hydra... They fly like long understable putters with more fade than a putter... Ive seen some throw aswome w/ them, but I never could. wizards/bangers, or a challenger like yours seem to be much more suitable for the kind line the hydra takes.