You can order it already cut, and order a sew disk to go with it. The other option is to cut it yourself with the likes of the Roland, and then use your own digitizing software to create the stitching.
TwillUSA, Stahls and Dalco all have the stuff you need. Imprintables offers the material, but not the sew disks.
You can also just sew the twill down manually using a normal sewing machine. It's not that difficult, especially if you just have a few to do. I've done several custom jobs and I just sew it manually. If you were going to do a bunch of the same design, then the sew disks would be a good option, but you will pay for them.
TwillUSA has some great twill. You can buy it by the yard and cut it yourself, and sew it yourself. If you don't have a cutter, you can even draw your pattern onto the twill and cut it with scissors. It takes a little longer, but works just as well.
We have the ioline 300 purchased through stahls. We do a whole lot of twill and the ioline works great. You just import your vector art, cut it, create stitches and save the file. The program does it all for you. The machine and software is costly but after owning it, it is well worth it if you have a big market for twill.
Tackle Twill 
