Ok, the story so far..
Just spoken to Tally (nice bloke). The 8 seater cost is £250 for the day (£31.25 x 8 ) & the 16 seater is £512 (£32 x 16). If, say we have the 16 seater and only have 15 bodies in it we would have to split the cost of the empty seat between us.
Sounds like we've got the 8 seater covered no problem and probably will be able to do the 16 seater with not much more effort; Tally says he can advertise it on his Facebook page, which has had people fill spaces in the past.
He also needs to get the go-ahead from the forestry commission, so I'll be emailing him in a mo to confirm the date - am going to go for Wed the 16th. Once he's got the go-ahead he only needs a couple of week's notice re which vehicle he'll be needing. I'd like to get it confirmed well ahead of then as I'm proper anal when it comes to organising things and want to know it's all sorted so I can look forward to enjoying myself
No idea how the payments side of thing will work, will ask Tally if it'll just be through his website once the date is arranged, as clearly you wouldn't want to be sending it to me & I could do without the hassle of collecting payments.
Think that's about it for now, will update when I know any more; if anyone else wants to come & play, post interest on here.
Edit: If anyone knows any other forums we could get people to join us from, do let me know. Have done same OP on Southern DH & MTB Britain, but no interest as yet.