Futaba F14 is a good set, and they are still available at quite competitive prices these days for an 8-channel rig. I myself use an FC16, which is an F14 with a computer bolted on.
If I was purchasing a new set today, I would go for a Multiplex radio, they're lovely with all the right features and controls built in for model subs. Ramesh (Mankster) has some good european links for good prices on these sets.
Regarding choice of submarine, this is very subjective. The first things to set down are your budget and the models subject (civilian, military), also whether it's important if the boat is a static or dynamic diver.
Regarding places to sail, I believe that Orpington had a fairly good lake. I organise three to four Dive-ins a year, which are always in swimming pools (clear, deep water, but easy to recover your model if the worst happens) and based in the South East, chiefly London and Hertfordshire. Two of these are held at Brockwell Lido in Herne Hill- not exactly round the corner, but not the other side of the country either. We get a very wide range of models at these events, from basic to complex.
There is a small charge to attend these events, as there are hire charges to recoup, but costs are kept as low as possible as these events are not-for-profit. I charge a nominal pound for spectators.
There is also the Summer Dive-in which is held in June at St Albans. This is a whole weekend and you can attend one or both days.
There are also various model shows in the South East like the Merstham Steam Show and Alfold where there will be submarines present. These are advertised in the events section of this website.
Andy