BPW and Jet Fin comments in...3...2...1...
I don't know if I totally should or totally shouldn't make the comment now. Oh well, here it goes.
Yes, the BCD you picked seems like a good choice and (if it fits) will make a good, reliable piece of gear with regular preventative maintenance.
However, try more BCD styles before you buy one. I would DEFINITELY recommend getting certified first. See if you can try different styles during your course (back inflate, jacket with/without tons of pockets, bpw, minimalist back-inflate) and see what you like. If you cant try them during cert then see if you can immediately post-cert. Also, post-cert you can figure out where/how/with whom you'll be diving and see what they're using/recommending/liking. Getting certified before buying gear, and then diving as if you had gear, is the best way to know whether or not you SHOULD buy gear. If you DO decide you like diving and will stick with it, then you can consider purchasing or just renting. Once you decide to purchase, hopefully you'll have enough dives to know what you do or don't like. I dove for 9 years without any gear besides mask/snorkel/fin.
And here's a plug for backplate/harness/wing assembly (BPW): They're great, simple, and NOT exclusively for tech diving. They're reliable, and people typically agree that they add slightly more stability to your dive. Diving in/around the UK often requires lots of exposure protection due to the cold water, so a steel backplate can shed like 10lbs off of your weight belt compared to the above jacket-style BCD.
Because fins were mentioned: I'm a fluid dynamicist by training, trade, and passion. I still haven't seen one "gimmick" that is anything but a "gimmick." If it seems too good to be true, it is. Fluid dynamics can be thought of in very simple terms with fins, and no "trick" can "increase" your propulsion by much....and if there were a trick, relativity and all current physics assumptions would be wrong.