It seems very hard to find two different bitcoin websites that will give you high enough odds to make that work. I didn't really understand the second part and your formulas are really not clean, you could have made it much simpler.
For fiat money websites, you do have comparison tools which show you sure bet opportunities like
http://www.bmbets.com/sure-bets/ (not my site fyi).
For bitcoin betting sites, there might be similar tools but none that I am aware of.
In order to find such opportunities, your best chance is to hover websites which have low overround (i.e. margin) like
https://predimarket.net (this is my site fyi) and make a little spreadsheet with predefined formulas computing the overround.
And what is the second part you refer to?
The part with the bookie and their odds. So you are basically calculating the profit based on what the bookie expectations or odds are but how can you take advantage of that?