For a traveling diver usually Aqualung and Scubapro are the best because any major dive destination will have an AL and SP dealer. So if anything happens while at destination you can find someone to repair it. Also they tend to have higher resale value if you want to purchase something else. Mares, Cressi, Sherwood, Zeagle, and Oceanic all make a good product but they are usually around the same price as SP or AL so I see no benefit in purchasing them. Others will disagree with me on this. Atomics are great, have good resale value but don't have the dealer network and cost more to service because of the packing lube.
That being said Deep 6 does sell kits so if you have a first and second stage kit you can find someone to repair at destination if need be. I don't know much about Deep 6 but they seem to be rebranded ODS regs like Hog and Dive Rite and some others. They should breath fine. Also Dive Gear Express is good service wise.
The Apeks set I linked to was quite common a few years back. From what I remember they were selling for around $300 - $350. Apeks is owned by Aqualung and are made in the UK. They are usually cheaper in Europe. While most European dive stores will not ship to the US, I noticed quite a few eBay sellers willing to ship worldwide. That could be another option.
As I mentioned previously, Seac is reputable as is Piranha. I have purchased some items from them over the years and have always been satisfied with their service. They also have service kits for those regs. At the price they are being sold you can dive them for a couple of years and then fleabay them and buy something else. You can get a first and second stage for around $200. These regs have been in clearance for a while so they may even cut you a deal.