I wouldn't have one with cats in the house - but that's because I've seen my cat do the mouse thing and it ain't pretty.
He brought in a live one the other day and half killed it before I could stand it no longer. I chased the cat, rescued the mouse (although would have probably been kinder to let the cat finish him off as he had little strength left in him), and let him go at the back of the garden.
I'd get a Ferplast Duna cage for it, because they have plastic sides, not wire ones - a wire lid though.
My hamsters stayed at my mum and dad's for three months when we were between houses a few years ago - their two cats were fascinated by them, but the hamsters didn't care - and the cats couldn't get them. The cats went a bit potty though.
ive had hamsters, mice and rats as a child and they were never fazed by the cats, although the cats were mezmerised!
we used to put the hamster in its clear playball thing so it could go on the floor and put some sellotape over the door to make sure it didnt come off. the cats would watch but move away if it came close.
Used to have a hamster and an elderly cat who were fine together. Ish. Hamster lived in a Rotastak thingy - you know, all plastic so no access for nosey moggies. My sister used to put it in those plastic ball things for some exercise. Every time the poor sod stopped for a rest the cat would pat it to keep going. With a really sadistic 'dance, little hamster, dance' look on her face..