Although I absolutely ADORE my MK25/S600's, I will admit I bought them used, and I don't think you have to spend anywhere near that much money for a good regulator for recreational diving. I don't know much about the Hollis regs, but I have an Aqualung Titan setup for diving singles, and it was very good value for the money. There is no need to go ultra high-end.
If you are going to do nothing but warm water diving, many BCs will do fine. I would always look for one that has trim pockets well up on your back, because horizontal trim can be difficult to achieve with all your weight in pockets around your waist, or on a belt.
If you are interested in looking into a backplate system, the Deep Sea Supply Kydex plate with the 17 or 20 lb wing is a very nice combination. It comes apart neatly for packing, weighs very little, and dives beautifully (I have the 17 lb travel wing). You do have to add a weight belt or, what I do, weight pockets on the cambands.
The one place where I absolutely agree with most of the posters above is that $185 for fins is highway robbery. Even considering that they include the spring straps, that's still almost twice as much as you need to spend. Consider a pair of the Dive Rite paddle fins, or the ones I have for warm water, the Deep See Pulse fins. They can be purchased on line for about $40, and then you add the spring straps to them. If at some time in the future you decide you NEED different fins, you can purchase them -- shops will always be happy to sell you the most expensive fins they carry
