6' 3" 250# (current) 275-288# (fighting weight.)
I've dressed pretty much the same for a number of years - BDU pants (black or blue - milder colour and baggy enough to move,) loose button-up shirt (winter or summer. Summer is usually a button-up, open, over a T,) and all my jackets are loose. Carry? 1911/1991 in a simple belt slide or SOB available to the left hand. I don't like IWBs - they tend to "dig" on me.
I'm big enough to make a 1911 disappear, so that's not much trouble. Sounds like you've got a decent rig for yourself (just happen to be a huge fan of the 1911, meself.) I'd carry full-sized - an "Officer" or a "Commander" would get lost on me...
If I had to wear something nice (like a suit,) I'd carry in a shoulder rig - balanced with two spare mags on the other side. Take your carry rig in when you get fitted, and a good tailor can make it not "print" for you (and still look decent when you don't have anything under it.) Again, being big can be an advantage.
Key element to any belt carry - use a stiffened belt! Enough are available (I tend to like Rigger's/Instructor's belts - double-layer Nylon with an internal stiffener and a "tri-glide" buckle, plus a triangular tie-in point for climbing/rappelling/utility use...) for a reasonable price that it's not a problem. They can also be had in Nylon or basic leather colours (black and brown, mainly - go neatly with nice clothing) so you can carry with a low profile. I carry enough stuff on my belt as it is ('phone, knife, G2, spare batteries, rescue hook, ...) that I need a stiffened belt even without a sidearm. A Rigger's belt may or may not fit beltloops on blue jeans - it's a 1-3/4" belt, and most jeans stop at 1-1/2" - but it fits neatly in my preferred BDU pants.
Why use a stiffened belt? What's the point in CCW if you spend all your time hitching up your belt? I've caught people carrying because they were farting around with their belt before I could see the sidearm print through clothing...
