Wheels...

you'lg have to purchase a new axle shafts whit a five bolt pateren and with the same spline count at the differential. Plus you'ld need to purchase new brakes, rotors,drums, shoes pads, calipers. so i'll be $$$$. if looking a new set of rims there should be plenty choices out there.

keep tha 6

Yes it is possible and a few dakota owners have done it, so a durango should be the same process. To do it right would involve changing axles and front wheel bearings (which are custom made), and then the brake rotors which are also custom. They do have those adapters that bolt on, but they are usually junky and are a little unsafe. Plus the track width on these trucks is typically so wide that if you add those your wheels will stick out past your fender flares. Its true there arent as many options out there for the 6 on 4.5 bolt pattern on these trucks but you should have no problem finding good wheels still. Check out dakota-durango.com and there are usually people selling nice wheels all the time.

Yes there's some adapter but you should not do that... find somme 6-lug wheels there's a lot

Be careful, to use adapters you will need hub-centric adapters (which have a funky pilot on the adapter) and part time 4WD may not be possible. You would be wise to stick with 6 bolt wheels, while they are more expensive, they are generally MUCH stronger and adapters generally will mess with steering geometry and wear out the bearings faster. Adapters without the hub-centric mount are VERY dangerous, they fail when stressed, cheapo adapters can look good, but they just don't last. Expect to pay at least as much for good adapters as for the wheels.