The key to making an IPA that lasts is less to do with the recipe and more to do with process. Be extra careful about letting oxygen in after fermentation, if you have a kegging system flush everything (carboys, bottles, tubing etc...) with CO2 post-fermentation. I'd also get it and keep it as cold as possible after it is carbonated. Hope that helps.
The recipe looks good, although I would probably use something other than magnum for the late boil and dry hop additions (more cascades would be fine).