It really does depend on the shaoe and size of your horses feet as to what fits them best, look at there website and size guide and take it from there. My horse has a long narrow hoof so I have been advised to go for the epics!!
Ditto above - totally depends on foot shape. I have one with short, wide feet so the Old Mac's G1's are good for her. Also use G2's and Boas (on two other horses) and they're all great.