First Recipe: Imperial Red Ale

I just completed my first batch of homebrew; I made an IPA using a Brewer’s Best kit. Now that I have successfully completed it, I would like a bit more of a challenge.
I am a college student, constantly on the move, so I don’t have room for a good setup (for all-grain), but I would like to create my own recipe. So I would like to make an Imperial Red Ale using extract. Here are the grains and hops I would like to try, as well as final goals:

9.2% Alcohol
92 IBU
Medium to Dark Red
Caramel Flavor, Citrus Aroma

1.090 SG
Base Malt (extract)
Weyermann CaraRed (20°L)
Briess Crystal 60°L
Briess Crystal 120°L
Briess Roasted Barley
Cascade - Bittering
Centennial – Bittering
Amarillo - Bittering
Amarillo – Aroma
Amarillo – Dry Hop
1056 American Ale Yeast

I know how to do the math, I just have questions on proportions. How much grain should be used, how much extract should be used, and in what proportions (individual grains as well) for a typical red ale (imperial)? I have no idea what types of flavors these grains produce either. How much LME should be used and how much DME should be used? I would just like a medium red color, with lots of bitterness.
Any recommendations/suggestions for this recipe?

I would go with 0.5 too 0.75% of the roast barley. Then 5% of each specialty malt.

The balance being the base pale malt. Figure it out in grain, then convert it to extract. In general, 7# of liquid extract is equal to 10# of pale malt grain.

I love Amarillo as a late edition or dry hop - it's awesome, but in the latest podcast Mitch Steele of Stone Brewing suggested that Amarillo did not work very well as a boil hop and is best used as an aroma hop. I would suggest trying Citra instead which in my experience makes an excellent bittering, flavouring and aroma hop.

As for the rest of the recipe I second Brewfun's comments.

It looks like you don't have a color dialed in yet, but I'd suggest you shoot for something south of 16ish SRM.  My last red ale was at 17 and it's too dark.