Think bigger - fire hose nozzles:
http://www.mcmaster.com/#fire-hose-nozzles/=lg4na5 Don't restrict the hose down to 1", the nozzle will restrict the hose enough for you.
You can use cam and groove hose fittings on the discharge hose.
http://www.mcmaster.com/#cam-and-groove-hose-couplings/=lg4om8 You can get those fittings from a farm supply store too. Just make sure that the discharge hose is rated for pressure, I don't know what pressure the pump will put out, but I'd hate to see it split on you as you're using it.
