On my recent trip to SPI, my buddy just used his old snowboard bag. He fit my 169 Litewave board, his 139 board and some wetsuits and harnesses. No questions asked leaving or coming back, they just made sure it was under 50 pounds. So if you can't find a golf type bag to work, a snowboard bag might be another good option. I think airlines are just used to snowboard bags flying in and out of Salt Lake, well during the winter at least.
I just got the Dakine Outlaw bag. Fits two kites, two boards no problem. Really happy with the bag but it does only hold boards up to 140. No questions asked with that bag too. Although, on the way back, the check in guy wondered why my "snowboard" bag was covered with sand

It's weird too, looking at the airline info, they charge for kite boards but not wake boards. So I was just planning on saying I had wake boards but was never asked anyway.
john l