Glock models, .22LR kits, Robert Boatman...
To correct some of the forum posts about the Glock pistols;
The Glock models have what is called a "safe action". In short it's a striker fired system that INCLUDES a small safety IN the trigger,

. The DoJ/ATF considers Glock pistols as DA only but I only apply that term to systems that have a exposed/external hammer.
For full details on the Glock line, see
www.BoatmanBooks.com . The non fiction books of the late author Robert Boatman explains nearly every faucet & fact related to Glocks.
Some tactics instructors & sworn LE officers like Massad Ayoob suggest using the NY+1 trigger(based on a system used by the NY State Police) but Boatman advised Glock shooters to keep it factory stock,

.
I've seen a few Glock after-market kits & barrels too. If you are set on a G-lock, Id opt for the latest Glock 23 .40S&W compact. You can buy replacement 9mmNATO or even better a .357sig barrel(that takes Glock .40 mags & no other parts/springs to use). You may find a model 23 .22LR kit too.
Renting & shooting handguns is smart. It's important to learn & understand proper methods to get the most out of it. As some gun press artcles & forum posts have shown, many "classes" & "rangemasters" have sprung up like mushrooms with the increase of citizen carry laws & new 2A/gun laws all over the USA. Many savvy gun owners know to take a 1 day class or workshop. You can gauge or assess a program/teacher BEFORE you drop a lot of $$$.
Real firearms/tactics trainers are "quiet professionals". They may answer your formal questions or provide background details but they won't brag, boast or sit around telling "war stories" of daring do(most of which is total do-do,

).
CF