hi im doing a swap and i have no clue where to get an engine

i dont want to buy a junkyard engine because i need a turnkey " brain, engine, ect.
it will be going in to a sandrail so i would need a reverse rotation cam because of the transmition no clue where to get that

i got a 1600 vw engine rite now but im looking in to watercooled i-4 due to mileage and gas prices hondas have the best mileage that i know of

can anyone help me with info

thanks