It's a good idea to brine chicken, period. There are lots of good brines. If you find one which works for you now in terms of time, taste and convenience -- fine. Just don't close yourself off to fooling around with lots of others. In terms of bringing flavors to the party, brines tend to be relatively subtle which lends some degree of freedom. But the caveat of not pushing flavors profiles very far in comps, applies here too.
One key to formulating brines is to remember that when tasting them by themselves is to remember they should not taste good, but way too salty. One key to using them is to remember they bring A LOT of SALT to the party, and to limit the amount of salt in your rub accordingly. None is a good starting point.
NEVER, NEVER brine chicken in a hot or warm brine (sorry, Bigwheel). Even if it's "only" a couple of hours, it's a major food-handling no-no and an actual safety issue. Furthermore, if your comp is inspected you will and should be DQd. You want the brine below 40F before or very soon after the chicken goes in (and before the inspector shows up!).
ALWAYS use the best and freshest chicken available. If all you can get is pre-brined, Mississippi/Arkansas mega-factory chicken that's all you can get. But if you can get better, use it. Chicken tastes best either immediately after or between 12 and 48 hours after slaughter (you don't want to cook it when it's still in rigor). If it means locating a fresh poultry operation convenient to the comp site... good luck with that.
Cooking at a relatively high heat will net you much better skin than going low and slow. However, you can cook low and slow, then tighten the skin later with high heat. This isn't limited to basting them with barbecue sauce and cranking the temp. For instance, you can get a little smoke into leg quarters, then bread and fry; or smoke a whole chicken low and slow, then hit it with a torch.
Of course, you can't use a torch for KCBS. But you can certainly finish on a high-heat grill.
There are an awful lot of ways to skin each one of these many cats. The more specific you are in terms of knowing what you're trying to do, the better the answers can be tailored to your situation.
For KCBS comp, the best approach just for skin is to bring a second, small cooker just for chicken -- so you can go high-heat and/or direct heat -- either for the whole cook, or just for the finish. Our best comp results came using an old "Portable Kitchen," cooking thighs over moderate, indirect (around 300F) until almost done, glazing, and hitting with high direct until the skin tightened and crisped. There's no reason you couldn't do quite well on a number of other pits: WSM, ECB, Weber Kettle, etc.
"Bite through" is better than "crisp," although you want both, ideally. Obviously you don't want flabby skin, but you don't want the whole piece of skin to come off the chicken with the first bite, either. A little acid in the brine helps promote bite through (I use a mix of citrus). So does not overcooking during the finish.
Still talking about comp, it's pretty much suicide to do anything creative with flavor profiles. Very few judges will be open to sriracha/orange. True for any comp using "trained judges," and triple for KCBS. Judges are trained to look for traditional, and (usually) want one of a few southern-regional or mid-Mississippi valley origin tastes.
BDL