Yes, commercial needles are pretty readily available up to size 50, but methinks this would require needles even larger. You can make and use needles up to any diameter, and be limited only by what you can handle.

If you're a knitter, join Ravelry.com (it's free!). Then, search for Laura Birek's Giganto-Blanket. There are currently 20 projects for this pattern, so you can see different results from other knitters. She sells the pattern for $4.99. She used slightly felted unspun superwash wool roving, and 1 1/2" (diameter) PVC pipes to knit it. She demos this on a Youtube video, too:

Good luck!!