For a 10-gallon batch, assuming 75% efficiency, you’re looking at an OG of ~1.070 and IBUs around 35 - if you want this to be a DIPA you’re going to need to step it up a bit, especially on the hops. I would add at least another 5lbs of base grain and use a high-alpha hop for the bittering charge, maybe 2 oz of Magnum, then hit it hard with late additions of a mixture of Perle and perhaps Cascade to get IBUs around 100.
WLP007 is a great yeast for a DIPA, or if you want to use dry yeast, US-05 works well, particularly in something with a lot of hops where the yeast character is less important (and you can pitch two packs per fermenter and know it’s going to finish dry).
For dryhopping, I like to reinforce the hops used in the boil and maybe throw in something else for interest and I like to smell some pine, so Chinook or Columbus or Simcoe would be good along with the Cascade and Perle.