Been there, done that, bought the wig(s).
First, men have larger heads, so you will most certainly need to buy a Large, not Regular. If you buy a Regular, it can fit, but will not be comfortable. And yes, this does reduce your buying option. My first wig was a Jon Renau, and they are nice – but it was a Regular. Shop around at Wigs.com, The Wig Company and Paula Young; you will find something which suites your need, and all of the above have decent wigs at good prices.