This is your best choice for a couple of reasons. First, using a bridge doesn't require that the two computers compete for "air time" if they are both doing something network intensive. Second, if you do have wireless interference, you know which component is having the problem.
Powerline networking has come a long way in the last 2 years or so. I didn't pay much attention to an article in my IEEE magazine recently, but there have been major improvements in performance and noise reduction. If the products are not already out there, they will be soon. So what you know (or think you know) about powerline networking has either changed or will very soon...
(Of course, doesn't help the OP since he wants his network
now!

)