i doubt a yb will be the answer.surely all the other 200sx owners that are drifting on whatever engine would be the best for you.you would need to make up mounts,propshaft,piping,somehow mate the 2 looms together,fuel system.the list goes on and on.it would be a cool conversion but it would be a pain.if it doesnt run right,who do you take it to?a cossie expert or a nissan 200sx expert.my friend david waterworth from scotland runs his 200 sx in the drift championships with a 450 bhp skyline engine and i think hes doing pretty well,why not go down that route as it will probably be easier,cheaper(i think a good cossie engine complete and gearbox will set you back about 1800 with all ancilliaties) and you will probably find it easier to get someone to work on it.what about the nissan 300z engine,they are bound to be plentyful!welcome to the site and good luck whatever you do!!