Right I think I have this right A pair of guinea-pigs should have a 4footx2foot hutch, right? So do they need access to a run at all times? Or would an hour or so of supervised time in a run a day be okay?
Yep that's right for two piggies.
It'd be good for them to have access to a run all day, but not neccessary.
An hour of supervised run time would be fine. But if you got a run that is safe enough then they could have a few more hours of run time a day. I think 4 hours is a good amount.
There's a wood framed run on zooplus.co.uk for about £42 and it's very strong and should be safe for them to be in unsupervised.