DIY, save a little money, but gives you some experience.
Radio Shack may still have an VSWR meter. If so, you can use it to tune the antenna. And true, normally the VSWR meters built into the CBs are not that accurate. If you decide to go that route, but don't know how to connect and tune the antenna, just post here in the CB forum like you did and ask away. We will give you plenty of info in how to do it. HTH you.
Freedom, a beautiful way of life.
Old scanners like me:
Pro-107, Pro-44, Pro-94, Pro-2006, DX-440