yes, the seats will swap. you will have to swap your seat tracks, but on 97 and older trucks, it's 4 bolts per seat. the seat frame should have the hole drilled for either reg cab or ext cab, but it's probably not tapped.
once you get your tracks off your old seats, put the front two bolts back in on the new seats. the back two should line up with a whole. then, you just start threading the bolts into the hole. they will cut new threads if the hole isn't tapped already. put a little oil on them just to help. and that should be it then.
as for the door panels.... yes, they will swap as well. they may not match the dash perfectly as it changed between 94 and 95. but they should physically go on. you will have to change out the metal brackets that are used for different parts. but it should pretty much be a straight forward swap.