You can usually get caps locally. Check your phone book under electronics. I regularly piece cap kits together locally when I need them "now".
Although really strange caps (big ones from power supplies and pinball machines) often have to be special ordered.
I have yet to find a monitor cap that I couldn't go into a store and buy local.
Also, remember you can always go higher on the voltage. You have to match the uf part, but the voltage part can be higher.