Yes, what part of Britain would you be visiting? Largest roe bucks are usually in the south and west of England. There is also stalking available in many parts of Scotland. Here is a link to the British Deer Society who may be able to help:
http://www.bds.org.uk/ also the British Association for Shooting and Conservation
http://basc.org.uk/ Their deer officer is Lewis Thornley the son of a friend of mine. My employer has an estate in Scotland which offers stalking packages for roe and borders the Queen's estate at Balmoral. I can come up with many more possibilities dependent on where you want to go.
Just a note Roe buck season in England and Wales is 1st. April to 31st. October inclusive and in Scotland 1st. April to 20th. October. No need for things like deer tags or game licenses and no bag limits. If you bring your own rifle you will need a sponsor to obtain your temporary visitor's Firearm Certificate. You can of course use the Estate Rifle and if accompanied do not require the temporary certificate; much the better option. The Deer Act puts a limit on the minimum calibre and bullet type that you may use and differs slightly between England and Scotland.
Come back to me on the PM system if you want further information. Lagopus.....