Do you have some 2 Row on hand? You could basically do a partial mash and supplement the rest with that 3.3lbs of extract. Maybe do a stout or porter. Use all of the chocolate, caramel and either some/all of the roast barley and black malt. If you do not have more extract or 2 Row to supplement, you are probably going to need to do a smaller batch than 5 gallons.
Bitter with the Northern Brewer. Throw the goldings in somewhere between 30-0 depending on if you want to add more bittering.
Could throw the heavy toast cubes in during secondary for a week or two for some additional flavor. I would not use the oak chips personally.