Check the website for the British Deer Society
There may also be some ideas/advice on the UK Stalking Directory forum
As to small details - under UK law you can borrow a rifle while on private land, during hunting activities, under the "estate rifle" ruling.
The alternative may be to bring your own rifle - but you'd need to be sponsored by a UK shooter & obtain a UK Visitor Permit - and we're more restricted on legal rifle types here (no semi auto centre-fire, so no AR or sporting BAR types)
Conversely, it's quite common here to see the majority of hunting rifles fitted with a sound moderator
You may be able to get two species in one hunt - but not likely to find three - but I may be wrong on that.
A friend has access to land just outside the M25 where it is purely CWD & muntjac, so he gets some days where both are taken.
Hope you manage to sort something out!