Welcome to the Fourm Family.
I am probably one of the largest members here (not bragging rather ashamed of it). Beltman is your best belt in my opinion. You are correct about using a good belt. That is half of the problem when it comes to carrying all day. The over half is a good holster.
I carry IWB appendix some with a Glock 43. I mostly carry between 3:00-4:30 when carrying OWB. I always carry concealed except when I am at my office. Of course it is easier to conceal IWB. I like leather holsters the best, but do use kydex a lot. I always wear t-shirts even when wearing a t-shirt rather than a button up.