What about buying a RIA or other lower end 1911, I love both my RIA's, and buying a .22 slide kit? Then the trigger is always the same between the two.
For roughly $700 you could have basically 2 guns
GSG is great. You're probably not gonna go wrong as long as you don't buy the Chiappa.
I'm gonna be the skunk at the picnic here (asbestos underwear on). But I'd strongly advise you to stay away from this gun category altogether. None of them are going to function as reliably as a purpose-built .22 pistol. From an engineering standpoint, you'd expect that, because the physics of getting a full-size 1911 style slide to recoil briskly under .22 recoil requires it to be made of a very light material (Al or cast magnesium), and the masses and spring rates involved have to be balanced on a razor edge to cycle reliably. I've heard some people say they want to "learn the 1911 platform," etc., but would recommend you get a conversion unit for a .45 if you want to go that way. At least you'll still have a rock-solid .45 when you tire of the .22 jams. If you really only want a .22, the Ruger Mk - series and others are comparably priced, and better guns overall. Most of the people I know who've owned them, once the appeal of the initial purchase wore off, eventually would admit they didn't cycle as well as a Ruger, Buckmark, etc.
That being said, if you're dead-set and "gotta have it," stay away from the Walther/Colt/Umarex. I had one and it's very nice as a conversation piece (I got baited in by the prospect of having something with both "Colt" and "Made by Carl Walther, Germany" stamped on the same gun...such was my weakness). It wouldn't function worth a crap, and rather than mess with springs and such, I decided to move it down the road. I want stuff that works, period (Rugers, Smith 41s, etc. have spoiled me).
I've also owned the Ciener .22 conversion for an Officers Model, and it functioned reasonably well, but it always irritated me that it didn't hold open the slide on the last shot.
I've heard good things about the Sig GSG guns, but again...I consider the entire category to be somewhat of an engineering "compromise," for people to whom the look/feel of a .45 is more important than function.
(To the comment above, about a threaded/suppressed gun working ok - it's a valuable observation, but in a blowback-operated gun that runs on chamber pressure, I've found that the backpressure generated by the suppression device will often make such a gun cycle _better_ than it does without the "can" in place. Once you're shooting a .22, you're not dealing with a locked-breech, recoil-operated gun with a battle-proven design and lots of "oomph" behind it anymore...you're dealing with a (low) pressure-operated engineering compromise between the looks of one gun and the function of another, which usually won't operate as reliably as either).
and good luck!