What Dave/Railkin suggests is quite intriguing. IMHO, a +14 composite longbow (like arcane) w/ mighty 7-10 or so, with minimal bells and whistles (stat mods, protections, spells, etc.) that produces its own arrows would be the perfect solution to the arrow swapping issue. I would love to run around with 3 or 4 bows that are all item slotted for instant access to the arrows required for the situation. Though without knowing how great the level req.s would be for the arrows, this could still be tricky as hiryuu points out.
Additionally, it would offer a very nice work around for the whole flatfooted issue that was inflicted upon us by the infinite casting exploiters: a very nice potential rectification!
It's possible with a 2da edit to itemprops.2da. Unlimited ammo comes in only a couple flavors in the standard itemproperties, none of them even close to any of the quivers, except perhaps the dung arrow quiver. So you have to edit them, and that takes a 2da. I THINK that's a serverside edit, not 100% sure, that would mean it could be done without a hak. So in theory it's probably possible, just a lotta work for marginal gain. I'll put it on the long-term todo list.