You definitely have the makings of a stout/porter or two. The yeasts you have will be fine. The Windsor will be a little fruitier and sweeter, the US-05 a little cleaner and drier. I don't know if you want one high=gravity beer or two regularish ones. So here's some quick and dirty recipe formulation.
Imperial Stout. Steep all your specialty grains and 1lb flaked oats. Use all your extract, plus another 3lbs DME (dark, amber, light all okay). Add 2oz Northern Brewer at 60min. Add 1oz Fuggles, Willamette, EKG or something similar at 15 min. Ferment with yeast of your choice. Approximate #s:1.085/1.020/8.5%ABV. 56 IBUs. This will be very roasty. You can scale back all the darker malts a little if you want. This beer should age well.
Robust porter. Steep 1/2lb each chocolate malt, Special B and Black Patent. Use all the extract. Add 1oz Northern Brewer at 60 min. Late hops optional. US-05 preferred. 1.054/1.012/5.4% ABV. 33 IBUs.
Dry Irish Stout. 1lb Roasted Barley, 1.5lbs flaked barley, 4lbs DME. 1oz Northern Brewer at 60. Windsor preferred. 1.045/1.011/4.4% ABV. 35 IBUs.