Jeff, your best solution is probably to purchase a plan from your ISP which allows you to run servers. That's likely to be a business plan, and will possibly be more expensive than your current plan. But running a server under your current plan risks your internet access; your provider could cut you off if they feel like it, or charge you (since the beginning of time, quite possibly, and don't laugh because it does happen) for the difference between your current plan and a business plan. This is the safest thing to do.
That said, it is possible to change the ports that your server is listening on. It may impact some server functionality, particularly if you go to install the connector on additional PCs at some point, but there's a tutorial
here that shows how to do this. Please read the first few paragraphs and take them to heart, though. If you're not reasonably comfortable with the intricacies of home networking configuration, there is the potential here to mess up your home network to the point where you can't figure out how to recover. If you're not comfortable with this, you're better off getting a friend or acquaintance who's more technically knowledgeable to do it for you.
I'm not on the WHS team, I just post a lot. :)
