Depending on what you used to plumb your current machine, maybe larger supply line from the tank. 1” should be sufficient if it’s not too long a run or too many elbows/restrictions. Though a lot of guys do recommend 1.5” for 8 gpm.
You should also have a spare unloader for it.
Apart from those two details, and the stuff you mentioned, I think you should be good to go.
I would probably go up to $1800 for an 8gpm machine that I knew was in good working order. I try not to spend more than 50% of original retail for used equipment.