I have done some FMQ on my Singer 66. Like Barri1, I recommend a vintage machine because of the larger harp area. I've also heard that vertical bobbins are supposed to be better for FMQ than horizontal bobbins, and this was borne out by my own experience, practicing FMQ on a 201 (horizontal) and 66 (vertical). The 66 did better.
All you really need is a reliable machine with plenty of harp area, and which has the option to drop the feed dogs (my 66 did not, so I removed them for FMQ).