0.75 lbs. Munich Malt
0.50 lbs. crystal 40
0.25 lbs. carapils
0.25lbs. Wheat malt
6.00 lbs. light DME
2.00 lbs. amber DME
1.00 lbs. corn sugar
First, get rid of the Amber DME and go with more Light or Extra Light DME. For an extract IIPA, you'll want to get rid of the Munich and Wheat malt, since these are mashing grains. If you still want them in there, but do not want to mash any grains, then Munich and Wheat Extract are also available for this goal.
If you want to upgrade to a Partial Mash IIPA, then mash some 2-row with Munich and Wheat. In either situation, the carapils is unnecessary since carapils is already inherent in extract.
If you want to make this all about the hops, and less of a malty alcohol bomb, I would consider reducing the OG to 1.070-ish. In addition, this will help with better final attenuation in an IIPA with a good deal of extract.
1.00 oz citra (13.2) - 60 mins
1.00 oz citra - 30 mins
1.00 oz citra - 15 mins
0.50 oz citra - 0 mins
1.50 oz citra - dry hop
Citra is a very tropical and fruity hop when mixed with other American hops such as Amarillo, Simcoe, Warrior, Centennial. It needs support from other hops like these to really shine. It's not a very good hop for a single hop IIPA.
However, if you're deadset on attempting a single hop Citra beer, then I suggest brewing a very simple, no frills, standard IPA at 1.055-60 OG. A base consisting of XL DME and Corn Sugar, that's it...maybe 3% crystal 20 or 40. It will be a cheaper brew that gives you a better idea of what Citra is about and you'll need less hops overall with no yeast starter.
Otherwise, here is a loose example based on a 5 gallon full volume boil IIPA at 1.070 OG / 1.015 FG:
1.5 oz. Warrior @ 60
1 oz. Simcoe @ 30
1.5 oz. Citra @ 10 (optional)
3 oz. mixed Citra and Amarillo @ 0 min. hopstand
5 oz. mixed Citra, Amarillo, and Simcoe @ 7 day dryhop
The 4.5 oz. total hops you were planning on is just way too little for an Imperial IPA, especially at 1.087 OG.
White labs WLP001 - California ale
A good yeast for a beer like this, but you'll need to pitch a healthy starter of adequate size (or multiple vials) for your intended OG.
http://www.mrmalty.com/calc/calc.html can assist. Be sure to plug in the yeast age and method of stirring, in addition to your batch size and vial count.
The only other piece of advice I can offer is to know your water. Get it tested. More often than not, IPAs benefit from some added gypsum to boost Calcium and Sulfate levels. Again, know your water before adding it.