In compatible upgrades CS5 and Camera Raw 7.4

Hi,

I have been shooting with my Nikon D 200 and processing my RAw files thru Adobe camera Raw 6.0 and finishing them in CS5.   Just got my Nikon D7100 which is not compatable with Camera Raw 6.0 but is compatible with 7.4  but 7.4 is not compatible with CS5??

I have light room 4 but like CS 5 much better.  How can I get Abodobe Camera raw 7.4 if I convert from Raw in that can I bring my image back to CS 5??

What tcan I do to resolve this dilemma

Thanks!