Ok, umm, you don't 'have' to buy a minimal!! I know the temptation to buy a shortboard is hard to resist, but riding a shortboard is so Very Very Very Very different to a swell board.
Really, you won't believe it, it's like learning to surf again. I surf a 7'2 minimal and a 7' funboard, and I'm kind of ok on those now, so I took el_timmo's shortboard (6'3) out to have a go on, and I could not believe how difficult it was. Paddling is difficult, sitting on the board is difficult, catching a wave is difficult, getting up on the board is difficult (although i did get up on it a few times, yay me!)...anyway It was like i'd never surfed before! and i knew if i carried on surfing it and never surfed my minimal again i'd probably end up with ridiculous technique..or I'd just not enjoy surfing all that much.
I was actually offering to give the board away in the water to anybody who looked competent and was surfing a minimal, i was desperate for an easier board to surf!
So there's my input about that, but it's a personal thing, just take out a shortboard and see how you get on I guess, take out a minimal, see how you get on, then chose which one you'd rather own.
As for cornish water in february, definitly a 5'4 suit. And gloves. And boots, about 6mil i wear, c-skins. A hat too perhaps, I certainly will be! Expect to pay about £150 for a suit and £30 for boots..
I'm just thinking about my ughly winter suit..so thick, I don't wanna wear it!! In a month or two though....