There is no way that I would use a belt without a click-in, locking buckle. Despite the hate on here, my SOE belt is hands-down one of the best belts made. HSGI comes really close, though, if not just as tough. If you attach a holstered pistol, extra pistol mags, rifle mags, or both, then you need a solid buckle such as Cobra style or Duty style buckle to secure your gear.
Also those big MOLLE belts are hot, bulky and uncomfortable. As good as HSGI is, I'd opt for a different brand such as Snaker Eater Tactical. Or even just a regular 2" duty belt from any of the high-end various manufactures we talk about here in this subform. There are even a could of 1.75" and 2" duty belts with MOLLE loops on the outside and/or inside and velcro to help stick to a velcro pants belt. Look at the Emdom USA CM belt for an option like that.
Alot of it is trial and error until you find a manner of wearing and using your gear that you are comfortable with. Kudos for going out and getting dirty with you gear. You'll figure out in short order what works for you. But seriously....use a belt that has buckle!