Carter - usually if there's a compulsory kit list, it's for a good reason - I'm guessing the Peaks' weather can change rapidly. You can get micro fleece gloves and hat which weigh almost nothing, so they shouldn't really be a problem.
I'll echo C-BtbM's comment regarding shoes - can't help you there, only you know what's comfortable. But if the Race Organisers are worth their salt, then you should be able to contact them and they will answer your questions.
Richard - that's the best thing about Ultras - you're allowed to plod!
Opinions vary greatly on the ultras you've mentioned, so have a look at forums or eg FB Ultra Running Community to get a general idea.
If you're a slower runner though, I'd suggest that you look if any of the races you might enter have cut-off times. I know XNRG don't - they do multi-day events and you can set off early and either walk, another time (an hour later) is for plodding runners and then another hour later the elite runners start - I've done a few of their events and really enjoyed them.
Hopefully other people will chip in with ideas.
Good luck with it all and your fund raising. Take home message though - get yourself booked on one! If you're planning for next year, there's plenty of time to train.