I went there, 20 odd years ago. They had trace combos in the studios if I remember correctly and all the gear was pretty good for the time... lots of electric drum kits I remember!
I feel a head would be a good shout, maybe something class D, headphones socket and an aux so they can practive quietly at halls or house share without the need of an amp and then take it to gigs where hopefully somebody will lend their cab.
For reference i took a hartke 4x10 and amp which I think maybe got used a handful of times. I have no idea what gigging in Bath is like these days, all the venues have gone I played in there, God I feel old..
Hope that helps and they have a great time I did, until I left to join a touring band.