RS Props are a very reliable group to get a commissioned costume from. Many of us on here have (including myself).
However, regardless where you buy, there is no guarantee it is approvable out of the box. Approval is all about how a costume fits your specific body shape.
The RS kit will be pretty close, if not spot on for you. But there's no guarantee.
Their Sandy comes with a very light weathering, so should be good enough for standard approval, but likely to need some additional weathering for Police Officer (which there are plenty of tips and trick available on this site). For SWAT, you will definitely need to do more weathering as you need to be screen accurate to a specific character (of your choice).
The other piece from RS you are likely to need to alter will be the blue milk containers on the back-pack. Again, there is more detail on this site, but their shade of blue isn't quite right for Police Officer status.
All that said, I personally can highly recommend their kit and customer service.
If you go ahead with them, start a build thread on here, get some photo's up of yourself in the kit, and we can give you some guidance on what, if anything, may need changing for approval.
Good Luck mate