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.