First Imperial Stout, Feedback please!!!

[imp81318]

As the title says, I am going to brew my first imperial stout tomorrow and I'm putting the finishing touches on the recipe, so I figured I'd get some feedback from some guys that are much more experiences than I am. What I am specifically interested in is whether or not I'm going to get that good heavy body typically associated with stouts. I brewed one other stout, an irish stout, that while it was a good beer, it didn't have the body that I was looking for. So here's the recipe (5 gallons):

15 LB Pale Liquid Extract

Steeping Grains (30 Minutes):
8 oz Black Barley
8 oz Chocolate Malt
8 oz Roasted Barley

Hops:
2.5 oz Fuggles (60 min)
1.5 oz Fuggles (30 min)
1.0 oz Fuggles (0 min)

White Labs WLP007 yeast in a starter.

Expected ABV = 9.9%

So I have a few questions:

1. Will this recipe give the full body that I'm looking for? If not, what can I add/substitute to increase body?
2. Is there another hop that I could substitute for one of the fuggles additions? I haven't used fuggles before, but they've been highly recommended to me by several people for heavy stouts.
3. My brew pot is only 4 gallons, so I am unable to do full boils at this time. How much of the extract can/should I add upfront vs at the end of the boil?

 

[JKaranka]

1) Yes, I find LME has more the issue of leaving some sweetness and body behind compared to all-grain or DME. I'd actually replace a pound of LME for some sugar. I think the total amount of roast malts is ok (1.5lb), probably towards the low end of roastiness but a lot of the flavours will come from the high alcohol content (dark fruit, sherry, etc.).
2) The 60m addition could easily be replaced by some neutral high alpha hops (whatever is cheap where you are: Warrior, Magnum, Target, etc.). You want to keep the Fuggles at 30m as that is going to be one of your main flavour contributions.
3) I've not used extract for ages, but I used to add about half towards the end of the boil. Better wait for someone else to reply.