Try Andy who runts the NTAC site, you can find it on FB. He has a techy guy he uses and you can do it all through his site or shop depending on what is closest to you.
Chest rigs tend to work better for people with a bigger frame, I have the opposite problem because I'm skinny.
UKTactical kit is top of the range, extremely high quaility and there kit is very adjustable, but its pricey.
Flectarn.co.uk do a lot of kit which is basically the same idea but with a smaller price tag.
Yes I DID do a search using the forum search and got no help there, yes I DID search on google and got a million and one results, but what I'm asking for a somewhere that dose custom Velcro patches that someone could recommend or has used before.