A good alternative regulator would be the aqualung titan or the SP MK11/G250V. The titan is a perennial best buy. The MK11 is a fine, relatively simple first stage, and the G250V is a re-issued classic. Another bullet-proof classic is the MK2. For a long trip with (presumably) little access to service, this might be a good choice.
I realize you're loyal to your LDS because they taught you to dive, but that's no reason to limit yourself to the one brand of products they sell. They do that because of the favorable terms an exclusive sales agreement with scubapro, not because SP gear is any 'better' and there is ZERO advantage to outfitting yourself in one brand. I like SP regulators and know a lot about how they work and how they perform. But I would never buy a SP BC, I just don't like the designs. I would probably only buy a new SP regulator as a last resort; my favorites are the older ones, for lots of reasons.
Despite the earlier recommendations, I would avoid beaverdivers if you don't want to be over sold as you say. Since becoming a member of scubaboard, he has relentlessly posted the forum with sales pitches and is the poster child for an "eager-beaver" type salesman, typically with very little actual knowledge of the products demonstrated in his posts.
Buying used is a good idea for a new diver on a budget; you just need someone to help you evaluate gear, and this must be someone who's not trying to sell you anything. In particular, buying a used BC is relatively risk-free and can offer a HUGE savings. I would buy a very simple, streamlined, feature-less back-inflate BC. The best of these IMO are rigid backplate/wing systems. But, zeagle now makes one called the 'tech express' or something like that that's reasonably priced and has received good reviews from lots of users. It takes time to get enough dive experience to be able to accurately evaluate BC type, and there's a big difference between the different types while diving. So it might not be a bad idea to just rent them for a while or buy a used, cheap jacket. One of the most common mistakes new divers make is buying an expensive, bloated 'high end' jacket BC that looks great in the shop but actually dives like crap.
There's nothing wrong with waiting on gear purchase and renting for a while. Remember you'll have to carry all this gear around, and they do sell dive gear in South Africa, just don't buy a tank there and bring it back to the U.S.
Oh yeah, there's probably no reason for you to take the nitrox course right away; it won't do anything for your dive skills, and nitrox is very unlikely to increase your bottom time as a new diver unless you're diving many dives/day at fairly deep recreational profiles. It has NOT been demonstrated to increase safety margins in recreational diving, although many people make that claim and it certainly is possible that eventually there will be data that prove the assumption. But it's a class that's often pushed on new divers because it creates demand for another dive industry product, nitrox fills. I've been nitrox certified for several years and I only use it in specific situations; four or five dives/day to relatively deep depths. But for 2 dives/day, it really won't do much for you unless you're so good on air and so confident in your profiles that you can easily push air NDLs without lots of repetitive dives. Does that sound like a typical new diver?
