Hey from Michigan

Hello, I'm from S.E. Michigan and I'm thinking of building a motorized bicycle with a 70cc lifan engine. I'd appreciate any help in picking out a frame and components and any pitfalls heading my way. At this point in time, I'm planning on using a stretch beach bike frame, a springer fork, having a suicide shift on the left. I don't know whether it would be better to have a left side drive in the back or go through a shaft and use the standard right drive?

I found a Giant Stiletto that has forward pedals and an existing jackshaft. I have a 70 cc lifan type engine. I'd like to mount it so it goes to the jackshaft and drives on the right. I am tentatively planning on mounting a disc brake on the front wheel and having it be larger, like 24". I'm thinking of making it look like a bagger and having a suicide shifter on the left. Just preliminary ideas. I'm looking for a stiletto fender in most any condition to work off of. Are you saying that the standard bike chain won't hold up? is the 420 chain what the engine uses or the standard bike chain? What are the designations of both?