can you only use Sub7 on a server or can you use it over the internet, if so, what port do you use?
Ok starting with this first point, you are asking us to inform you about a program you intent to use over the internet, in so one can only assume that you don’t have permission to use this program on the computer you intend to use it on. In so no on here is going to help you commit this act. Now if you where perhaps looking for information about how to protect yourself from this program and in so asked a question accordingly you would be more likely to get a response that is positive. Now here a though for you, if you wish to be a hacker for a challenge then consider this, using someone else program show no skill no understanding and will only make yourself look lame, however learning about computer systems how they work and working out for yourself how to gain access shows greater understanding, not as lame as just point and clicking and letting someone else code to do the work for you. but this is still only one side of the coin as it where, if you learn enough to be able to see and infd your way into systems, well done you have learn a lot but you have only learnt so far, they REAL challenge that shows really understanding is not only to be able to find systems holes and find ways to gain access to them but also to find the way to prevent this type of attack fix the hole. That show a lot of skill.

where can I get the latest version? I have 1.7 I think
No one here is going to tell you where to get the latest version. I suggest you take the version you got, set up a little home network and play learn how it works, learn how to use it, and learn how to defend against it. How to remove it if your infected and then try to explain how to remove it to someone whom is less computer literate then yourself, explain how it works to them, explain why its a risk. To be able to explain the concepts and applications to someone whom does not understand something to the degree you do is a skill and shows a deep understanding of the subject matter. But then that is if your prepared to do the work and try to gain that degree of understanding, if not then I have one more suggestion. Find somewhere else to ask these question because no one is going to help you here.

Kindred69