Reddit mentions of Resident Evil North America BSAA Logo Embroidered Hook Patch 4 Inches

Chris's shirt is a little challenging. It's a sort of short-sleeve quarter zip. This link will take you to something that isn't quite the right color, but close to the type. Also affordable.

Color is still off, but I think the material and type are a bit more accurate than the one above, it's just more costly.

This one is a bit better as far as color is concerned, though not perfect. At this point, if you're skilled with sewing and the sort, then you can shorten the sleeves.

That all said, here is a BSAA patch. I believe these are the same kind that came with the game's original special edition release, so it's fairly accurate. And Chris was operating out of North America. Barring the above, you could get any sort of green athletic shirt and put this on there. Word of warning, I believe the materials for a lot of athletic shirts don't take to ironing very well. Safer route is to sew them on. Probably for the best, as I never trusted iron on all too well.

The harness is what is a "tactical h-harness". There are many types so you can search them out. They're not too costly, though his is a little interesting. I usually find them where the harness loops that connect to a mid-section belt (amazon search for battle belts) at 4 points. His wraps from the front to the back around his side, and have a loop that extends to his belt. Not the greatest explanation in the world, sorry. The short and skinny of this is that you can get away with just getting an h-harness and looping it around itself instead of trying to make it reach your belt.)

Notice that there is a translucent waist belt? Chris doesn't have that. His h-harness basically just forms a loop around his arms he can just sling around himself. He also has some pouches on the back of his harness.

This link will direct you to a cosplay shirt for Leon. $20 ain't too shabby, but I don't know the quality.

Hope this helps! Best of luck!

EDIT: Got my formatting backwards...