Consider taking a look at the Hatsan Galatian III QE. Got mine new from Field Supply for $650 during a sale, synthetic stock option, stock out of the box mine shoots 40 fpe with JSB King 25.39 grain. Been told with a few simple tweaks and a regulator it's easily a 50+ fpe rifle for at least your 20 shots. Has 13 round magazine with a 2nd in the butt stock to make reloading easier but the downside would be having to watch your pellet length to make sure they fit in the mags. Tuned by you or maybe by Baxter Walton who would coax everything possible out of the rifle, it would fit everything you're looking for except the pellet length choice.
Some questions.As you already have a Hatsan .22, what would you want the .25 to do that's better? Lighter? More power? Got bigger critters in mind? Longer ranges in mind?Lot of good rifles, many in .25, but the above tends to help narrow the search.for me, my first .25 was for bigger critters. Not farther away, I still tend to "indian up" to them and get inside of 50yards, I just wanted the "thump" of a .25 and heavy pellets for things like opossums/raccoons and an occasional nutria. 50 foot pounds seemed like a reasonable goal (although it ended up I could get 60 if wanted) and the shot count didn't need to be high (never get a dozen shots in one hunt on those critters).BTW...am also a pump-filler, so I limited myself to smaller air volumes, low shot counts because of that small volume, and ruggedness. I really don't mind plain wood, so long as it's well sealed (tend to do that myself as the hidden parts are almost always raw wood). When it's bad, will put on a thick coating of paste wax and NOT BUFF it off.Knowing the above helped me make up my mind....your requirments likely are way different, but at least if you nail down what you're going to use it for, likely to find the choice a lot easier.
I did not consider .30 cal due to ammo cost,around my area .22 cphp is sometimes hard to find and I can find .25 jsb 25 grains for $8 for 200ct.Just as cheap to shoot as my .22.
https://www.amazon.com/gp/aw/d/B0035KH2V2/ref=mp_s_a_1_9?ie=UTF8&qid=1483419579&sr=8-9&pi=AC_SX236_SY340_FMwebp_QL65&keywords=25%2Bcaliber%2Bpellets&th=1&psc=1Just an example