Given Aaron's fine and kind offer - I'd be taking him up on that... and save yourself the money for now.... ( buy one later if you feel the need... )
I think you mentioned getting a local machine shop to do the rebore ? Can they re-cut the seats, which from the photo don't look bad (?).
New genuine guides ( LGJ100880G ) are only 99p each from craddocks, so I'd replace them "automatically" at that mileage - and then get the machine shop to press the guides in and then re-cut the seats - though I reckon they might just need a tickle, rather than a full re-cut. Give the valve stems a once over as well - they might be fine; turners have new at a bit less than £6 each.... so ????
I don't know the seat limits off the top of my head - but it'll be in the rebuild manual, which is here:-
http://landroverweb.com/Pdf-files/300Tdi_Overhaul_Manual-Land-Rover.pdf
Don't forget new stem seals as well !!