I am 5'9" and 148 lbs.
But, having said that, IWB is all I use for concealed carry. I feel that this provides the best concealment - while still allowing access - over a greater variety of conditions. There is virtually no chance of exposing the bottom of a holster or even the slide/barrel. While there is always a feeling of pressure, I've gotten used to it, and have gotten to the point where I feel naked without it.
It very definitely makes a difference which holster and belt you select. I am quite fond of the Wilderness Instructor belts, if they go with your clothing. These are very stiff and will not allow the holster/gun to sag away from your body, but unlike leather belts which have holes in a fixed position, they allow infinite adjustability.
Thus far,
for me, I've found that this type - in this case a Galco Royal Guard for my Glock 19 - is the most comfortable, although its design does add thickness/bulk.
http://www.sightm1911.com/lib/review/pix/royal_guard_250.jpg
There are also the types with belt loops or clips on either side of the handgun. If your gun is heavy these will support the weight a little better, and there is no additional width/bulk. They
are a little more trouble to fasten and get in just the right position, as well as needing some break-in time to conform to your body shape. The type with a clip retention is easiest to put on or take off. I am "on the fence" about the Kydex IWB holsters. The one I have, while definitely allowing easy
reholstering, also allows every edge and corner of the gun to contact my body, making it less comfortable.