How about a two-in-one... Chose the Glock of your choice in the caliber your prefer and add a Advantage Arms 22lr conversion kit
Mike beat me to it with this advice. Its what I would do for sure...
Get yourself a G20 (or 21 if you are partial to .45 instead). Only those of us with big hands can enjoy this size of Glock so it would be a shame for you not to get one. Call Police Ordinance or TSE and get the AA kit for it and you are GTG. Work with the .22 kit to learn the trigger and build proficiency, then you can switch to 10mm/.45 for a bigger boom when the rimfire becomes boring.
If you go for a G20 (my choice) you can also get a Lone Wolf conversion barrel to allow you to shoot .40 S&W too. One pistol and three calibers to choose from...
