5.11 Tactical Men's 1.5" Trainer Belt, Strong Mesh Construction, Rip Resistant, Matte Steel Buckle

Is this a 2 ply belt, or at least reinforced? i like a stiff belt for iwb carry

Should I buy for my pant waist size or one size larger?

Will this belt hold an IWB holster with a Glock 19 and 2 spare mags? Sometimes with a 4.5" flashlight and a multi tool.

What is that style of buckle called?