Rover owners: Cam Belt/Tensioner/Water Pump changing question

Evening all.

For a change I'm actually going to ask a technical engine related question

I'm thinking about changing the cam belt, tensioner and water pump (as well as a general all round service), but due to the limited access was wondering if I should call someone in to do this? I'm not useless with the spanners and am quite able to follow instructions and do a good job, I'm just concerned that it could prove problematic due to access.

Don't get me wrong it's not the filters and plugs side of it, just the cam belt, tensioner and pump.

Is it a straight forward job to do? Or is it best left to the experts?

I'm thinking one of the recommended mobile mechanics, if anyone knows of one that covers South Lincolnshire?

Also, if I did use a mechanic, would it be prudent for me to obtain the parts (genuine MG) or let them supply them?

Thanks in advance for any (constructive) input