Figured it out, just edited a userstyle meant for a different site to my tastes. Changing the px on max-width makes it a fixed, centered width however wide you like:
Code:
/* BlueGartr.com - Fixed width centered edited from script by Avgust*/
@namespace url(http://www.w3.org/1999/xhtml);
@-moz-document domain("bluegartr.com")
{
body
{
max-width: 1050px !important;
margin: 0 auto !important;
margin-top: 7px !important;
}
#overlay
{
width: 100% !important;
}
HTML
{
margin-left: -5px !important;
}
}