D2 front driveshaft replacement
 

I see a special tool sold by lucky8 and AB. Is it necessary? Just looks like an extension

9/16th wrench, a few extensions and a ratchet and you'll be good. I find it easiest to put the front end on jack stands, and jack up one side of the rear axle so the wheel is off the ground. Lay under the truck and use your foot to spin one of the front tires and you'll be able to get the driveshaft to turn making accessing the other nuts a little easier.

I have an electric impact gun so that should help

You won't be able to get a socket on the bolts at the angle they go in at. You'll have to use a wrench.

I see Lucky 8 has their front drive shafts down to $188 at the ebay store. Is there any negatives to their drive shaft?

That's the one I got but I called them direct to save them the eBay fees. They have been great to work with.