I'm very tempted to dreg up memories of Gecko45 but I'll take this a legitimate inquiry.
If you're getting shot by any type of long arm, any "normal" ballistic vest isn't going to help. If you're job is the type to warrant a heavy vest daily you'd already have the training and experience and not need to ask here. An add on special threat plate is about as much as I might recommend, Pro-Tech makes a good one that handles a lot of threat rounds beyond a normal IIIA vest.
Protection Level: What are you carrying? Get a vest that will stop your carry round, or just go for a IIIA and call it a day. Are they heavier and hotter, yes but still not that bad. You get used to it after a couple of weeks. I work next to a river in Texas, it's about as hot and humid as it gets, and a IIIA isn't that bad. The dark blue polyester uniform is much worse.
Carriers: Get 2, swap them out at the end of the week and wash the worn one. They'll last about 3 years this way.
Undergarments: Anything moisture wicking is great, but a plain cotton t-shirt is fine too
Each company has it's own terms and conditions on warranty, replacement etc. Bear in mind ALL vest manufactures have a 5 year limit on everything. The vest is still quiet usable, just not covered anymore.
Find a cop shop in Chicago to get fitted for your vest, or follow the directions on the order form EXACTLY when measuring (and have some else do the measuring impossible to do it right by yourself). An ill fitting vest is a miserable experience.
-Jenrick
