Go with the 105th edition, too many 09's. I was originally going to get the 105th. They are really classy and alot less of them on the road. seems like this website is loaded with the 09 springers. Be different.
There are actually more of the 105th anniversary 2008 FSXTSSE2's out there (serialized at 1,050 bikes) than any one color of the 2009 options. There total production run of 2008 was also higher (2,500 vs 2,172). Below is the 2009 production count for the 2009 year. I can't locate the breakdown for 2008 other than that there were 1,050 anniversary models made in addition to the 2,500 other colors.
Yellow with Orange Flames - US (315), Foreign (95), Total (410)
Blue with Silver Flames - US (550), Foreign (212), Total (762)
Black with Greem Flames - US (745), Foreign (250), Total (995)
Special - US (4), Foreign (1), Total (5)
Total overall production - US (1,614), Foreign (558), Total (2,172)
So, your best bet is to grab the Yellow 2009 because it is the most rare (not that I'm biased or anything)!