In reply to Taurig:
I'd say best go with someone who has done it before. You will want to go with someone else anyway, for speed of digging!
I'd be surprised if we get a cold enough freeze again this year to do it, but there are still a few good bits of snow clinging on if it does freeze again. Not at all sacriledge to do it outside of Gorms, but bear in mind that the Gorms are the only place to do the poo project, so take your own poo bags elsewhere!
Metal shovel definitely easiest, saw can be helpful too if hard snow.
Sleeping bag wise, I always take a 4 season and bivi bag, but I guess it depends on how warm you sleep and how well you construct your hole.
If it starts blowing a gale, don't close the entrance! Instead, get up regularly and clear the spindrift so you don't asphixiate!
I'd say get someone experienced to take you first time!!