Buying a used engine, sight-unseen, from the other side of the world is a serious crapshoot, dude. Granted, you could probably sell some of the cosmetic bits on here to recoup some of your cash, but in the end, you're looking at basically a stock engine of questionable quality for your entire budget, which would mean you come up short on critical items such as oil, filter, plugs, wires, belts, hoses, coolant, and so on.
You will be happiest if you just do a simple stock rebuild. Stock lump is PROVEN to 400hp. Put a smooth $1000 into a fresh, zero mile stock engine, enjoy driving it while you break it in, and THEN decide how to invest your remaining $1500 to make it a screamer.
You do NOT need Frankenstein 2G piston setup.
You do NOT need a Cyclone intake manifold.
You do NOT need fatty injectors.
You do NOT need porting, a valve job, or any other headwork beyond decking for the MLS HG.
You do NOT need any more headaches.
It's going to start warming up before you know it, man. You've got about three months get that sled sorted, or else you're still going to be f***ing with it in the summer. Keep it simple. Keep it maintained. Keep it reliable.
Don't buy into the hype. A reliable, running GVR4 beats a clapped-out, Frankenstein shitbox "racecar" any day of the week.