Well, I imagine since your asking here this is not the best answer. But, if you can afford to have someone else mix it for you there are a bunch of solid benefits to letting the professionals do it.
First, the obvious extra ear training on their part. Second, their gear and software will be far superior to yours. Third, mixing can be a really good place to let someone else take the reins. Once you do all that work on a song it can be really difficult to step back and look at it as a whole piece of music and not just the parts you painstakingly recorded. Just my IMHO. I personally use Ableton and I use the Ozone mastering plugin.