Yes, Brian Carlwell was top-50, and I believe he had an offer from Michigan State. Though they were also going after Tom Herzog who was their top big option.
Jamar was a 3-star kid outside of the top-100. Chester was a 3-star with offers from Binghamton, College of Charleston, and a few others. I believe Charles Jackson had offers from Auburn and UGA, but mostly because they wanted him to play football as well.
And yes, Jamar would have been a very good 4-year player for us. It's a shame what happened with him.
Nonetheless that 2005-2006 combo was an unmitigated disaster. Perhaps the single worst recruiting performance I've seen when you consider how high Illinois was as a program when those classes were recruited. 2007 rebounded slightly when you consider McCamey, Tisdale, Mike Davis, etc., but even that was a disappointment considering who we were targeting -- IDKWTI, Evan Turner, Moore, etc. Not even going to mention Rose, because that was never going to happen.
Follow that up with the 2008 0-fer (missing Shumpert, Liggins, Darius Miller, Michael Dunigan, Matt Humphrey, etc.), and that 4-year stretch should go in the dictionary under "recruiting disaster".