I actually just downloaded Beersmith (the trial)... and reworked the whole recipe as a partial mash, 5gal batch, 3 gal boil. Everything is almost the same, and I will be adding the pilsner malt extract late, and I have it at about 68 IBU. Just really changed the amount of Columbus to 0.63. Doesn't really matter if i'm at 65 or 75, just as long as it tastes good. But I do appreciate the help, and I think I will be buying the full version of Beersmith.
I've heard of some beers being dry hopped multiple times, so I might do that with Cascade/Amarillo for one week and then add Centennial/Ahtanum for an additional week.
Edit: After getting used to the program some more, it turned out I clicked "add after boil" for the pilsner LME... I changed it to 15 minutes before the boil is over and the IBU's went down, so i increased the initial columbus and cascade back up to 1 oz and now i'm at about 57. Works for me.