A few more quick points for a "armed professional" or pistol packer...
Get a lined belt. It will be stronger & support the wt/size of most handguns & related gear(mags, knives, cuffs, cell phone/PDA, etc).
Use at least at 1.5" wide belt for a firearm the size of a Glock 19/23 or SIG P229 or a K frame S&W revolver. It's wide enough to support a weapon for 6/8/10 hrs at a clip.
Some gunbelt makers like Galco, Ken Null & Mitch Rosen make gunleather belts that narrow out front to 1.25" so you'll look like a quiet professional with most coats, vests, jackets.
Finally check the belt loops of the pants or men's slacks. They should be wide enough for a 1.5" belt or be strong enough to support a firearm/gear.
Duluth Trading, Woolrich, 5.11 & Blackhawk all cater to that style in basic colors like black, navy, OD, tan.
Some simple plans and a few smart picks will keep you on track & comfortable too.