A few things:
1) 17lbs of extract is a ton! I get an OG of 1.12 just from the extract, not even the spcialties
2) Get a trial of Beersmith or Promash or beertools. They al have free trials, pick you favorite and buy it. That will help yout get your recipes at least numerically correct
3) If you are really interested in making your own recipes, look into books (Designing Great Beers is a good one)
4) You don't need to buy two yeasts - search for "starters"