I put type 2 swift seats in mine, no welding required however do need to be a problem solver and have a good mechanical aptitude to attempt doing it correctly.
Biggest tip is to remove the rails off the sierra seats and the rails off the swift seats, turn both up on their ends, and see which bolt hole you can reuse and which ones you have to redrill.
Then insert flange nuts on cable ties/wire up behind the redrilled holes. Its fiddly but not too bad if you put your tongue in the right spot. Drivers seat is easier as you can pick up some captive holes from the old rails. Then flat bar is required to support the recliner mech to the side of the seat front to rear and hide it with the plastic trim.
however on the bouncy road the seat upright doesn't give enough support for a squishy ride and can be a bit savage, the base however is brilliant. I just lean forward when I see storm drains
