Upload & Sell: Off
the OP wants to run the same catalogue for Ligtroom on the 2 machines .
as far as im aware this is possible . ive not used smart previews yet , but in theory this is what they are designed for.
I did just migrate from a WIN7 machine to a new imac , i upgraded to LR5 at the same time , but i just pointed LR5 at the cat file from my old machine and it did the rest . Obviously i have to re find my images (I had done tne prep before the change so this was quick and easy) , but this step should not be an issue with smart previews