Also, don't be afraid to go direct to Mike at CCI
if you're looking for anything special (non-black anno, longer barrel, special setups, etc). It's also good to browse the site's galleries and find exactly what it is that you want.
Yes, the feedgate comes with it, but you only get one. It's a rubber piece and gets nicked up when reloading. Not a bad idea to have a few spares around. Order them from anyone that sells Phantoms.
Also, get yourself the detent ring set. It's $6 well-spent. The stock barrel is a bit on the larger side (so it can accomodate all the paint out there) and with small stuff (draxxus?), you'll get some rollouts. Detent rings prevent that. I also recommend the trigger shoe strictly as a comfort issue.
As for the grip, some people love the .45, some love the M-16. I know people that swear by both. It's all preference. I myself use the .45 and find it more comfortable. Plus it can accept any number of different grip panels (Dye stickies?) as well as a bottom line or stock without modification. Downside: it's a little more expensive. Consider getting a stock if you're not opting for a bottom-line setup (I recommend the VSC). Stocks will steady your aim considerably.
Lastly, the barrel length is mostly personal preference as well. Are you using 12-grams or CA? Do you care about gas efficiency? Are you going to put a red dot or other site on it? 11" is going to give about peak efficiency. Shorter or longer you'll loose some. The 6" and 8" give you the worst. Longer barrels are easier to site down, but if you'll be using a dot site, it doesn't matter. Lastly, is there any preference that you particularly have? You mention you usually use 14" barrels. Perhaps you'd be more comfortable with something at length? I personally use the 16" with the muzzle break and it's just amazing... but then, all the stock barrels are.
As to where to get them, I don't know of any 'bad' CCI dealers. Mike picks some excellent people to sell his products. You should be well-off with anyone. As to shipping speed, if they have it in-stock, you'll have it within a week. If not, well... Just make that your first question. Call up and ask, "Do you have -blank- in stock?" Can't go wrong. Lastly, if you just want plain black, look at eBay or other places for a used one. Be careful about eBay, though, as Phantom prices there tend to be very close to the cost of a new one. If it's only $10 or $20 less than a brand new one, it's not exactly worth it, right?
Good luck in your search, I hope you get everything you want!