Hi and welcome to the Gigabyte Forum.
The GA-X58A-UD7 will most definitely fit into a mid tower case no problem. In fact when I first got mine I installled it into an Antec, if I remember correctly, 900 case and that was with full water cooling also. To be fair it is quite tight and that is why I moved up t a HAF 932 full tower case for the extra room. It will probably be more the worry of whether your chosen heatsink and fan will fit as some of them are enormous.