Big Belly Jim:
I usually go to Mark's myself, but I assume you have already looked them up.
Mark's is my go to! I have gotten a couple polo type shirts from there. I've noticed recently that their t-shirts are diiferent. They feel great, but are cut smaller. The XL is tight so I tried the 2XL. I know this gain is turning me flabbier than I've ever been, but there's no way I should be in 2XL yet. I will be and I will graduate to the big mens store, but I'm not there yet. I'm about 215lbs.
Funny side story about Mark's. A few weeks ago, I tried on an XL polo in their change rooms. It was ridiculously tight. Checked the price tag and the sticker. Yep XL. Weird. Tried on the 2XL and was swimming. It didn't make sense. I checked the first shirt again and the while the tag and sticker was XL, the label printed on the shirt was M. Found an actual XL and its good. I enjoyed explaining the problem to the cashier. She had an embarrassed grin on her face...agreeing that medium wouldn't work.