Is my fuel pump in my 1999 Durango going out, or could it be something else?

It started stalling out on us a couple months back, usually when you slow down to stop or turn but it also stalls when just driving. It usually happens within the first 15 min. of driving. It has to sit for a few minutes and up to a few hours before it will restart. When it starts to stall the rpm's will drop fast sometime pumping the gas will keep it from stalling for a few minutes but it chugs and sputters and dies out quickly there after. Now we can hardly get it down the steet with out stalling. Before it had gotten so bad we took it to a auto parts store and had it checked for codes, they said it showed cylinder misfire( I think #3, but cant remember) so we replaced all spark plugs and wires. My dad thought it was the ignition coil so we replaced that and the battery. Check engine light had gone off for a while but now its back on and we can't get it to go far enough to have it checked now. Thinking of towing it to dealership. Any ideas would be greatly appeciated.