Maybe you should get some advice from Noah's Mommy - one of her cats is in an enclosure.

I suppose it would depend on the amount of time you would spend with the cat, and how big the enclosure would be. Maybe you could look at adopting a PAIR of cats, so they would have each other for company. Are you thinking about adopting an adult cat? I can't help but think that an older cat would be better suited to an enclosure than a kitten who needs to be socialised, litter-box trained etc. Sometimes shelters get multiple adult cats from the same house, so at least they get on together.

It's similar to the dilemma I recently had re the dog - outside vs shelter! Unfortunatly my $%^*&* Landlord would not give me permission to erect a fence

Good luck with whatever decision you make!