I'm not really a big guy, but I think the fundamentals stay the same regardless of size. IWB is going to balance concealability, comfort, and ease of access in a primarily shorts and t-shirt environment the best in my opinion. Personally if I'm wearing anything but gym shorts I have a G23 in a Comptac Mtac tuckable hybrid holster, and gym shorts gets the Keltec PF-9 in a cheapo little clip IWB holster similar to an uncle mikes I got off Amazon, as long as I tighten the drawstring nice and tight and don't do any cartwheels (not that I could ever do a cartwheel) retention is fine. Pocket carry is possible, but the "pocket" nines and j-frames need a really deep pocket to work with and think back to the last time you were trying to dig your car keys out of your pocket to get out of the rain? Now think about Can you draw quickly out of a pocket under stress? For a full size caliber, I would recommend the XDm 3.8 40, or G23 in a good IWB holster, don't go get the nylon stuff from uncle mikes or whatever cheap stuff they have at the gun shop. Galco kingtuk, crossbreed supertuck, or the aforementioned comptac are all "hybrid" holsters, basically a kydex mold for strapless retention and a leather backing for comfort. Or go all leather if you're into that kinda stuff
A brand new PF-9 can be had for $250, the XDm's are around 600 or so, a used gen3 G23 can be found for around $300. The PF-9 or the pricy PM-9 by Kahr are excellent options if all you want is one gun that you can carry year round, 8 rds of 9mm is nothing to be scoffed at, but personally, I like options when I carry, variety is the spice of life.