Vest, if there is any way at all to justify wearing a vest or a loose cut Sport coat then you should be covered, (pun intended. I have Eddie Bauer, Orvis, a nice plain black leather vest Also 5.11 and a 24.7 and a loose fitting sport coat that I have not gotten to wear in the last few years dam it to hell. A great many folks can justify a vest of some sort, especially if you are an engineer, IT of any kind at all, Dock worker, shipping/warehouse worker, If you work in an office then a nice decent non-biker Loose Leather vest should work just fine. When you buy a new suite from now on, if it's one that gets fitted then tell the Tailor that you carry and would they please left the jacket out a bit or whatever they need to to help conceal your weapon. I flat out, no hesitation say that you will NOT be the first person the Tailor ever heard that request from. Well unless it's their very first day on the job, and the guy teaching them how to be a tailor hasn't gotten around to having a customer order one yet. I have gone into Men's Warehouse, Saks, Brooks Brothers (that guy actually blinked but didn't say anything) And said that very same request. Nobody cared in the least.
Oh and back in the day (way ancient history) the Chinese Tailor in Hong Kong that I had 3 suits made. He not only didn't blink, he said he allready knew I carrying and please step into the back so he could measure me with the holster on and asked if I ever wore a shoulder holster. I said yes he said bring it next time I came in for a fitting and he would take new measurements for that. I do so love Hong Kong. Damn near nothing will even get most merchants there to even raise an eyebrow. And they keep your measurements on file forever. You can call or write and order another suit, they ask any change in body weight and if so where, and after they have that answer you get your suit 2 or 3 weeks latter fits like you were there again. and about half the price and twice the quality of most men's suites short of Italy or England.
OK back to the point. Which is, find something loose that you can justify wearing pretty much anywhere at all, even if you have to get a different one for out shopping and one for work, what ever. Set your the leading edge of your holster just to the front of your pelvic bone, Hopefully not particular close to your pocket and either use a IWB holster or an OWB that has the belt go through the loops crosses IN FRONT of the holster and then buckle it tight enough that your pistol snugs up close as possible to your side with out making your pants bunch anywhere. OH one last thing Baggy Sweat shirts work very well just less justification to have them at work or out to dinner. Coaches jackets are also great, Heck anything bulky is going to go a long way to concealing your weapon. The trick is having a reasonable reason to have what ever you pick on unless you are at home or with friends that carry and it's a BBQ. Actually for the record I have a Black 5.11 Vest that has CZ, Dan Wesson, 2nd Admendant, NRA and a couple other patches that I wear daily and not a single person that would concern me ever gave me a second glance. And if that vest isn't a giant walking sign that I am armed or more than likely armed then I have no idea what could be more obvious than open carry (and IMHO, if OC is legal where you live I would never on my worst day actually open carry unless I was first responder to a crash or disaster.)