My '99 has factory installed A/C. There is a little compartment underneath the v-berth where everything is mounted. I think its 7K BTU and it will freeze you out if you're not careful.
As for the benches, mine is a stepped-hull and from what I've been told, there isn't much room underneath of them anyway. On a flat-bottom like yours, I'd think you'd have more room. Good luck!