One real issue is that this is the deepest of deep motor parts. The nominally $200 you save on a $430 new assembly can really bite you in the ass here. The H's unit comes with the actual tuned counter balancer shaft assembly for that production run of crankshaft. It's driven off from a gear machined into the crank, so these parts have "worn in" together. The E-Bay item is advertised as used, no counter balancer is shown, you are 4,000 miles away, so if it frags a day or so after you get it back together you'll never really know why; at that point you are really out of luck. The good news is that the second or third time in things are easier....
I assume you are planning to do all the work? What is your experience level? What tools & workspace do you have access to?
Your new piston /barrel assembly is about $380 from H's, and even more on e-bay for some reason. Just a premium piston for my Bullet is close to $240 by the time it gets to me, plus there would be $60 - $100 for cylinder boring charges. $380 may not be such a bad deal for all-new, properly fitted top-end parts.
All up you are easily looking at $800 - $1200 worth of parts & machine work. Start saving up for that or possibly look for a
complete running used engine for similar money. At least than you'd have spares. Once you have to replace bits that require splitting the cases, things get pricey real fast. Short-cutting deep motor work only leads to heartbreak and more broken equipment.