Great idea, and you can do that.

Within certain limitations, you can choose what ever name and address you want for you site;

http://companyname.realvalue.net    or

http://www.companyname.com

All e-mail addresses will be completely personalized to what ever you choose.
This will give you a much more professional image;

yourname@yourcompany.com    or
yourname@realvalue.net

NOT something like mj23423@ix.zero.networld.com