All Grain Imperial IPA advice please...

I'm trying to get together a recipie for an Imperial IPA, kind of a cross breed between Hoptimum and Hop Slam. Was hoping to find some advice here. Here it is...

Original Gravity: 1.084
Final Gravity: 1.020
Bitterness: 99.7 IBU
Alcohol: 8.5% ABV
Yeast: White Labs California Ale (WLP001)

14 LB Pale Malt (Maris Otter)
2 LB American Munich
8oz Cara-Pils/Dextrine
8oz Caramel/Crystal Malt - 20L

first wort 60+ mins 1.0 Chinook
boil 45 mins 1.0 Simcoe
boil 30 mins 1.0 Amarillo
boil 15 mins 1.0 Citra
boil 15 min 1 Whirlfloc Tablet
boil 10 min 1 Yeast Nutrient (WYeast)
boil 1 min 1.0 Citra
dry hop 7 days 1.0 Citra
dry hop 7 days 1.0 Amarillo

any thoughts, concerns & suggestions would be greatly appreciated!

MO would probably make an imperial IPA a bit cloying. I would use an American 2 row and sub a pound of it for a pound of corn sugar. You want a IIPA to finish really low (1.010 to 1.012) in order to highlight the hops. Don't worry, there will be plenty of backbone to a beer with an OG of 1.084. Also, you can never have enough hops!

Also, make a very large starter or pitch two packets of dry yeast.

Thanks!

I made the change using briess2 row in hopville but still come up with FG of 1.020 any other suggestions?

Nothing wrong with using 2-row and sugar in this, but I disagree that MO would make this cloying. it will definitely add more nuttiness and more malt character, but it certainly won't effect your FG. its added character can take away from the hops tho, so if thats what you want to shine, id cut back on it.
I'd move the amarillo and simcoe to the end of the boil tho. At 45 and 30mins you're kinda wasting the great qualities of them as the flavor will be very minimal and any aroma will be gone.
also, all calculators just use an estimate based on the average attenuation of the yeast and won't be adjusted for mash temps or sugar. lower mash temps = lower FG, sugar = lower FG.

we all have our tastes, but i would use regular 2-row, and move the amarillo and simcoe to the end, as they're good, clean hops, and that's what ipa is all about