Funny I'm making the same into a dipa with a touch of Apollo. But I love Amarillo, also cascade and I've made some good iPas with Galaxy. To many I love just to name 3.
I really like those. Chinook for the dark dank biting bittering, Centennial for its flowery aroma and smoothness, Cascade for its citrus hints and smooth aroma.
Coumbus for bittering then late addions of Simcoe and Amarillo, dry-hopped with all 3. This is my go-to for IPA's. There is just something about Simcoe and Amarillo together and I love how dank Columbus is.
Going American, I like Centennial, Amarillo, and Cascade. English, I'd go EKG, Challenger, and probably Target. I also like to use continental hops in my Belgian IPA, where I use Styrian Goldings and Strisselspalt, and I could see tossing some Saaz into that mix as well.