I have no idea about that particular gun but I do know a bit about ccw as I conceal a full size 1911.
In my opinion it's all about the holster and belt, and I'd highly reccommend carrying about 3-4 o clock inside the waistband with a pancake holster. Get a real gun belt imo. I use the wilderness instructors belt with added stiching for stiffness. I'm sure the leather gun belts are great too but they are expensive and have wait times. Concealing a large gun is all about having it tight to your body so you don't feel the weight flopping around.
Crossbread supertuck, comp-tac get the best reviews for kydex style (I've never tried either). For leather expect long wait times, but they are worth it. The best is supposedly Milt Sparks VM2 but has 6 month wait. I got a black ops from purekustomleather.com that I love.
You might have trouble finding a good holster for an HK 45 just because they aren't as common as your snub noses, glocks and 1911s. Especially if it has a rail. I'd say forget the rail if you plan to carry it, but if it's a smoking deal for that one I'm sure you can work around it.
