They also make 1911's in .38 super, 9mm and 10mm,
AFAIK, maybe more calibers. They have real tiny ones in .380 and most can take a .22 conversion kit. They are still super popular guns and the mods seem to be neverending....like 911's. ParaOrdnance makes them with wider frames to take double-stacked mags. Otherwise, the three main sizes are full size, Commander size and Officer's size. Commander size actually has a full size frame and a shorter barrel and slide by 1". A lot of the parts are interchangeable, but there are so many hotrodded guns out there nowadays, even from the factory, that the aftermarket parts often have to be massaged to fit.
I got a stainless Springfield Mil-Spec that was missing only the barrel......for $275 delivered. I wanted a guide rod, beavertail, polished ramp barrel, custom hammer and trigger. I got them all on ebay pretty cheap and had them fit and installed when I sent the gun out for refinishing. You gotta have all your mods done before refinishing. It's a super, super nice gun now and I have about as much into it as a new, stock one would have cost.