Hello
Here you can find bot the 32-bit and 64-bit versions of Java:
https://java.com/en/download/manual.jsp
And about installing the doc server V2.0... you can just upgrade your current version without installing the old version.
There is only one remark I would like to make. If you upgrade the existing one, without uninstalling the old one first, It will run by default on port 8181, which might give you some problems with the 3DConnection Space Mouse.
If you uninstall V1.0 first, and then install v2.0, If will by default change the ports to 8282, so you'll avoid the 3DConnection issues. But when doing this, you also need to re-install the documentation itself, not just the doc server.
I hope this makes it a bit clear.
Kind regards,
Dennis