I dont think you need to be great at fmq for rulers. Rulers themselves provide the precision needed. You get rulers for the machine you plan to use. I have a high shank machine and long arm so I buy long arm rulers. I also have low shank so if I wanted to use my rulers I can only use on front and sides because you can't use the rulers behind low shank feet. So if you have a low shank machine you need low shank rulers. You can add fmq to ruler quilting but it is not necessary. Also make sure to have a ruler foot.