A constitutional crack bleg from an attorney of note

I got a call from a notable attorney who asked for help on a crack-related claim of unconstitutionality.  Here is his follow-up "bleg":

As I stated today in our telephone call, I was Brian Gall's trial attorney and want to take on a new fight.  I am interested in attacking the constitutionality of the statutory mandatory minimum for crack cocaine as found in 21 USC 841(b)(1(A)(ii).  Specifically, that statute creates a mandatory minimum sentence of 120 months for possession of over 50 grams of crack and for over 5 kilos of powder cocaine.

My client’s specific situation is that he pled to one count of possession of crack, with the factual basis of 85 grams of crack.  He had no prior criminal history and was 19 when arrested and 20 years old when sentenced.  In 2006 His guideline range was 120-135 months and because he refused to cooperate with the government he received the minimum sentence he could under the guidelines and 21 USC 841(b)(1(A)(ii), i.e. 120 months.

He has now filed a motion for a sentence modification under the new crack guidelines, which put him at a range of 87-108 months, but the government is opposing this due to the mandatory 120 month sentence found in 21 USC 841(b)(1(A)(ii). I would like to file a motion attacking the constitutionality of 21 USC 841(b)(1(A)(ii) mandatory minimum, as it employs the same 100:1 ratio that has been modified in the amended sentencing guidelines as well as criticized by the Supreme Court in Kimbrough.  Any help, ideas, research and motion drafting assistance from any other attorneys facing a similar situation or interested in taking on this fight would be greatly appreciated.  I can be reached at The Alternative Law Office of Marc Milavitz, 1733 Canyon Blvd., Boulder, CO 80302; (303) 442-2166 (phone); (303) 440-4515 (fax).   

Any assistance you or anyone else can give me is greatly appreciated.