Yes, did cam belt myself, Its fidley getting belt on,but not that bad a job.
As far as oil quantity for a classic, 4 litres for g box and 1 litre for dif.
If you are going to trouble of doing belt and tensioners its silly not to do water pump.

If you not confident in doing belt then its safer to get it done by garage, Jafa quoted me best price, before i decided to do myself.