Roy Williams? No way. One of the league's most overrated safeties. Big hitter, poor in pass coverage. Ask Santana Moss about that.
If you had to take a lineman, LB, and DB, I'd take:
Freeney
Urlacher
Reed
LB is a tough one, though. You could go with Lewis, Al Wilson, Antonio Pierce, Brooking, or others and be just fine. Urlacher's having a great season, though. Watch out for Jonathan Vilma; he'll be a top 5 LB for years to come. Marcus Washington is a stud as well.
Reed makes more plays in the secondary than any other player in the NFL. And no one is as dominating on the line as Freeney. Just ask any offensive lineman, including hall of famer Jonathan Ogden, who Odgen himself admitted got dominated.