If you buy that premix cup the math is already figured out for you;-) Premixing only sucks because of the additional smoke at idle from my experience. Mix a little heavy, like 40:1 and idle around a lot and you can foul plugs. Or at least the old beast 250 EFI would.
From the post title - I was wondering if it took a rookie to respond or a rookie to pose a question. So I was drawn into this one...
Sounds great, giving her some love. You might be a little green but now your not a rookie.. LOL! Your on the right path and these guys are experts at parts.