I’m not exactly sure what your question is about the DAZ Studio files. If you’ve already downloaded the software, I’m assuming you downloaded a 32-bit version and a 64-bit version, so am I correct in assuming you want to know which of the two you should install?
If that’s the case, it would depend on what your computer’s operating system is. I’m not familiar with the different Mac OSes and which are 32-bit and which are 64-bit, but if you are on a PC and running Windows 7 on a fairly new computer, you are most likely on a 64-bit operating system. If you are on an older computer running Windows XP, then you could be running a 32-bit operating system, but you would have to check because I believe XP did come in 64-bit as well.
Once you determine which operating system you are using, then you should run the appropriate DAZ Studio installer.
OK, as far as the Newsletter subscription, you should log into your account dashboard, and about half-way down the list of links on the left you should see one that says Newsletter Subscription. If you click on that link the next page you see will have a checkbox next to General Subscription. Check that box and click the Save button and you will be automatically registered to receive the DAZ newsletters.
Hope that helps. Any other questions, don’t hesitate to ask.