I thought about it last week and came up with this.
My preference would still be a for a late single national primary day, at most 2 months prior to the Convention.
If not that, then spread it out over four consecutive Tuesdays. Twelve or thirteen States per week. Start with the smallest states. Award points to winner equal to number of State Electoral Votes. Instant runoff system, with winner takes all. 270 points required to win. And close the primaries to declared Republican voters only!
For 2012, with the RNC Convention the week of August 27th. Primaries would fall as follows.
June 5
Alaska (3), Delaware (3), Montana (3), North Dakota (3), South Dakota (3), Vermont (3), Wyoming (3), Washington, D.C.* (3), Hawaii (4), Idaho (4), Maine (4), New Hampshire (4) & Rhode Island (4) representing 44 EV’s.
June 12
Nebraska (5), New Mexico (5), West Virginia (5), Arkansas (6), Iowa (6), Kansas (6), Mississippi (6), Nevada (6), Utah (6), Connecticut (7), Oklahoma (7) & Oregon (7) representing 72 EV’s.
June 19
Kentucky (8), Louisiana (8), Alabama (9), Colorado (9), South Carolina (9), Maryland (10), Minnesota (10), Missouri (10), Wisconsin (10), Arizona (11), Indiana (11), Massachusetts (11) & Tennessee (11) representing 127 EV’s.
June 26
Washington (12), Virginia (13), New Jersey (14), North Carolina (15), Georgia (16), Michigan (16), Ohio (18), Illinois (20), Pennsylvania (20), Florida (29), New York (29), Texas (38) & California (55) representing 295 EV’s.
I think I’d even be fine with them starting the week of July 10. Still 3 weeks for a nationwide tour by the winners leading up to the Convention.