If CGTrader has the STLs that you need, you may be able to find someone in you local area that can print them out. Find out first if there is someone who can do it, and what they charge before purchasing any models. If you are doing several buildings, it might be cheaper to get your own 3D printer and print them out yourself. 1:24 scale buildings can be very large and take up a lot of material, not to mention, they could take many hours, or days to print.
If you decide on a 3D printer, get the largest print bed that you can afford.