The shop will try to push you to buy what they can sell and therefore I would always be skeptical of their advice. The time to start believing advice you get from shops is when you hear the same advice from different shops or from divers you trust.
First, about the BCD. Mares makes good BCDs so if want to buy the pro tec I don't see any reason why you would be dissatisfied with it. I hear it can be partially dismantled for travelling as well which is supposed to be a handy feature. I don't know about that but it's worth looking at it if you travel and dive locally with the same BCD.
About the SS1: Personally I don't like safe seconds on the inflator. They were popular back in the day but that was only because the regulators we had at the time lacked enough low-pressure ports to put a dedicated octopus on it. Moreover, if you do actually have to use one and make an ascent then your buddy will be using your primary, which has quite a short hose for air sharing, and you will have to manage ascending and venting air from your BCD at the same time you have your inflator in your mouth. I always found that a bit awkward. Personally I would recommend a normal octopus for you for 2 reasons. (1) if you are travelling and for some reason you need to use a different BCD (say yours breaks) then you will need to rent a BCD and a regulator because your safe second is attached to your BCD and (2) you will be diving some of the time with "insta-buddies" who will very likely have learned on a "normal" regulator setup and are unlikely to be familiar with the use of an SS1.
Scubapro regulators have a good reputation and they're solid. However, other regulators are also good and well made. Brands like Mares, Aqualung, Apeks, Scubapro, Atomic all make good regulators and there are others too. It's hard to find a *bad* regulator these days but make a list of brands people suggest and look at those first. My advice is to just shop around and buy what you want. You'll have to get them serviced once a year so if you buy them from a shop clear across town you'll have probably drive there once a year to get them serviced. Your local shop may service them but they may also only service the brands they sell. Check in to that.
As for the computer, I don't like computers on the console, especially if you're travelling. If for any reason you need to rent a regulator then you'll have to get them to take your computer off and put it on the rental reg. moreover, a computer on the console will be stored with your gear and theft on vacation is a real possibility. If your computer gets stolen then you will have to rent a different one and skip a day of diving because of that. A wrist worn one, say the size of a large wrist watch, may be a better choice for you because it's more flexible and you can wear it all day to keep anyone from stealing it. Several brands of wrist worn computers are available, Suunto, Mares, Scubapro, Cressi are a few. Features and your budget will guide you to the right one.
hope that helps.
R..
