If you've never cut metal at all, you'd be wise to practice a little, but otherwise, cutting your own hole is pretty cheap. I got my acrylic at lowes diy center, and they can cut it down to the dimensions you need. If you go this way and also plan to paint it, cut first, paint 2nd. Doing it yourself can be rewarding, but don't just dive right in. I'm looking into different glues and such to keep my windows in place that I've done myself, since epoxy is not doing the job. I've also been warned not to use super glue, since it can fog the acrylic.