First time in Business or First, you're going to find any of the BA's long-haul products really cool. If you like the idea of doors, then go for the new stuff, but most people find them at least partially gimmicks.
In Business you have the old seats which I rather like (you need a window seat) or the new Club Suites. In First, they're all pretty same, although in the A380 they're larger (makes a difference mainly if you're a larger person yourself).
Enjoy!