grtactical.com has Bravo Company uppers for about 425. These are tier 1 uppers. Nothing to upgrade or change. Everything you would want an upper to be. Also has some LMT's for about the same price, maybe a little more. I would go with Bravo comp. Good luck.
Bought my lower at the last gun show. Plan on getting the upper in Feb at the next gun show. They can make up any configuration you want. They use DoubleStar components. I've heard good things about their products. Tracy
I will add my support to these brands. A few others to consider would be Sabre (they makes the best barrels of anybody out there), Noveske (outstanding quality, but expensive), and Daniel Defense uppers.
In addition to checking out the G&R Tactical, and BravocompanyUSA.com (both of whom I've purchased from), check out PKFirearms.com. They have a number of these rifles available as complete uppers, and they have very good prices and great service. On their home page, drill down under their "Complete Upper Assemblies" section, they have Sabre, Noveske, and Daniel Defense uppers all in stock right now (no I don't work for them, just a happy customer).
Also don't overlook the other link on their home page, "PKF Custom Upper Assemblies." These are name brand uppers that their shop takes and adds extra, desirable name brand parts to, such as a quad rail, BUIS, enhanced triggers, and so on. These are often great bargains, I've bought one of their PKF Custom uppers that was an enhanced Sabre, and it is an excellent rifle.
I have a Bravo Company mid length and it is better than everything else I have ever owned. They have great pricing right now for the holidays, on their uppers as well as their BCG and charging handle. You can find a removable carry handle just about anywhere, but I would also look at the LMT rear sight. It has the same controls as the sight on the carry handle, only it doesn't include the carry handle and will make it easier to put an optic on down the road. I hope this helps
I've had good luck with PK Firearms recently. They had some items in stock that I couldn't find anywhere else, everything listed on their site is in stock and ready to ship, and they were very prompt about getting me what I ordered. Also, as others have mentioned, it's hard to go wrong with BCM or LMT.
You can buy a good upper from many companies now a days. Most companies allow you to choose options that you desire. This gives you a chance to make sure it has the things included that are important to you. If you buy an already put together upper. Just make sure it meets your needs.