As you're experiencing some problems with older games on your A1200 then you might want to look at a "Minimig v1.1". That way you get a machine with a real 68000 CPU (which can be cranked up to 50MHz in the menu for any flight simulators, etc), OCS and ECS chipset, and you can run either the ADFs or WHDLoad from a Hard File on the SD Card. You'll be able to get your whole collection of games on a 2 or 4GB card.
If you plan on using WHDLoad then get the 4MB version and not the 2MB one.
When MikeJ's FPGA Arcades appear in numbers then don't be surprised to see Minimig v1.1 machines appearing on eBay.