what would i have too give to complete an engine swap? ecu loom etc matched to the engine?

there is one with a busted gearbox locally but a good engine, it would be handy for me to empty my sheds into it while i sort them out so i dont want to use it, just buy it, sell what i could so hopefully it would be free/cheap storage then out the rest when i was done tidying and making everything fit better in the sheds

just thinking i wouldnt want to sell an engine bare if it then needed 1000 worth of bits matched to make it work

the van is 800 (too much) but theres a bid in there somewhere maybe i;d get my money back at 600?