I have done alot of reading here and I have a question about primes..I have two daughters who are into dance and tumbling..I have seen pictures taken with primes in the 105 range, which are awesome, but would one like that work with dance, or action pics? I have a D60, but looking to upgrade to a D7000 due to the focus points, faster burst rate, HD video and higher ISO for low light shooting..So, would a 105 2.8 do the job vs a kit zoom?