Dude, why reinvent the wheel? Everyone that's used a Walbro is saying that work...like you said, if you're not going for some crazy 1000hp setup what's wrong with the walbro?
I understand you're trying to "future proof" as much as possible, but later down the track you'll need to change the fuel lines and pump setup again if you want to take full advantage of the 1000cc's....so why not just go a single Walbro for now? $130...vs ????