I have a SmartCarry that I occasionally use; it's a good design, but I find it a little unnerving to have the barrel pointed at my genitalia as I draw the weapon. For this reason, when I use the SmartCarry, I never carry with a round chambered, heresy to some here. The other thing I'd note is that, depending on the size of your handgun and your build, you may or may not find it uncomfortable when sitting. It's not an end-of-the world thing, but I find that the grip of my Glock 26 pokes into my admittedly less than svelte stomach when I sit.
As one who dresses pretty much the way you do--a tucked shirt and casual pleated pants--certainly the most comfortable option I've found is a small pistol (Sig P238) in a pocket holster (D.M. Bullard). Of course, you're limited in the size of handgun you can carry in a pocket holster.
When, for whatever reason, I want to carry more than a pocket-sized gun, I go with a tuckable IWB holster. I've actually amassed a fairly impressive collection, but the one I like best is the Galco SkyOps. It's light, very thin, and easy to put on or take off. I have a one other Galco, a Milt Sparks, and a Minotaur, and I find all of them a bit less desirable, though the Milt Sparks Versa Max 2 is such a nice piece of work that I sometimes use it for just that reason. The problem I've had with the IWB holsters like the Versa Max 2 and the Minotaur MTAC is that the two widely-spaced clips make it significantly more difficult to don or remove the holster from my belt. On the other hand, the advantage that those two have are a bit more stability and the added comfort of a layer of leather between my pistol and my skin. The latter is not as big an issue if you wear undershirts.
There are some who do not feel at ease unless they have access to a larger caliber weapon with a hefty capacity, but generally speaking I am content to carry my little Sig in a pocket. If you find that approach appealing, it's certainly the most comfortable and offers faster access than a SmartCarry or tuckable IWB. You just have to ask yourself if you're comfortable carrying a mouse gun.
Also, if I might take a moment to restate the obvious, darker colored pants and/or patterned shirts make it less likely that your concealed handgun will be detected by others. I'm a strong proponent of the notion that, if you're carrying a concealed weapon, it should really be concealed. You may find that you'll have to make some wardrobe adjustments to enhance concealment.