I already have a subscription for Lightroom on a PC. I have the chance to purchase an iMac. Will Lightroom run on the iMac and do I need a separate subscription for Lightroom on the iMac? If so...can you point me to where I can get it?
You do not require to have two different subscription for Mac and windows because Creative Cloud applications are platform independent.
And you can install it on two computers at most (can be a mac or windows / or both macs/ or both windows).
Please check your system specifications mentioned by F. McLion as well before going for it to avail the maximum benefits of the subscription.