Dude, no need to take your ball & go home (EDIT: glad to see you didn't, since we posted simultaneously). The folks on the thread are just trying to be polite & make suggestions & help (and since concealed carry is so personalized, it's very hard to make suggestions about anything other than what one has tried personally), but I think some of us (myself included) may have allowed the four-page thread to distract us from your very first post:mr.72 wrote:Never mind. I shall go back to figuring this out on my own.
I know for myself, I focused more on your description (though mentioning you're a cyclist probably would have gone further than weights & measuresmr.72 wrote:I am about 190lb just a hair under 6' tall and wear size L (42) shirts, 33-34" waist jeans that are not "relaxed fit" but more "regular fit" like 501s. My shirts are not tight but they are not oversized (I can fit into a M ... and some of my shirts are M or even S depending on the maker... so I guess even L's are oversized a little bit). I don't wear a stiff belt routinely. I'm all ears if there is a way to carry my Sigma 9mm with an IWB.(emphasis mine)

Unfortunately, what I would have said (again, based solely on my own limited experience, others here may disagree) is that you'd be very hard-pressed to make a full-size pistol work in ANY kind of WB carry (inside or outside) without a belt of some kind. Just the weight of the pistol alone will make it almost impossible. Long story short, the gun needs something to hang from that isn't going to be going anywhere. (think of the Smartcarry - it's essentially an under-the-pants belt with a pouch attached that the gun hangs from) Will the pants you wear, in the style you wear them, support the weight of the gun without any kind of belt at all? Only you can answer that, since none of us can feel what it feels like to wear the pants you wear. If the answer, as I suspect, ends up being "no", then neither IWB nor OWB is likely to work at all, and it's time to be practical & realistic and consider something else (either carry location or the gun itself).
The only other thought I have would be perhaps the Pager Pal, but the relative "tightness" of the fit of the jeans might preclude that. There's a video on the site you can check out, and I know one other individual here has tried it and found it lacking.
As with everything, YMMV, and we all really do hope you find what works for you.
JT