One thing I noticed on the 80/20 site the other day is that they have a new (To me) extrusion HT series which is tubular framing with offset holes. Its more like a kitbot frame material than the usual 80/20 that we all know and love. I don't know if I would use it for a frame due to its size (and therefore weight), but it could be good for a super structure. Here is the catalog:
http://www.8020.net/PDF/HT-Section-1.pdf
It only comes in 1.5" square right now. Some of the pieces have flanges built in which could be useful. Due to the fact that we can make something lighter by welding 1/16" tubing I dint think it would be great for 177, but for a team with less manufacturing and/or engineering resources it could be an excellent solution.
Eric