I think if you check the seach function you will get more info than you need about the area hotels. In my opinion it depends on what you are looking for, the Sheraton Towers is nice, newer, with a Club floor & great views of the Lake & the Chicago river, the River North Westin doesn't have a Club, but does have the 'heavenly beds', the Westin Michigan Ave is older, but centrally located. I'm not sure about parking rates (as I use the L when in the city) but I'm sure its expensive.
I think the outlet center you are referring to is Gurnsee Mills (?), located north of O'Hare, right on the main highway to Wisconsin. There may be others, but that would be the easiest to get to. I'm sure someone on FT can give better directions.
Good Luck & enjoy Chicago