There are numerous handguns that will handle shooting school training, but with some qualifications. A handgun's surface must be smooth and edge-free. Beretta, Glock, HK, SIG and Ruger semi-autos fit the bill. So does the Smith & Wesson Sigma. However, there are a sharp edge or two around the trigger-guard area of many standard-model Smith & Wesson semi-autos.
These name brands are reliable, too. Your customer is better off with a used specimen of a proven top-quality gun than a cheap new model that doesn't work or chews up his hands.
Be particularly careful of the 1911s you sell students. Some work better than others. The brands I've found most reliable are those from Colt, Ed Brown, Kimber, Les Baer, Para-Ordnance, Springfield Armory and Wilson.
Be certain the 1911s you sell have a beavertail grip safety. The old-standard grip tangs do terrible damage to the web of a shooter's hand by the end of the first day. This happens often since...