I'm sure it would be fine, just heavy as all get out. I made a 2x3x4 cage out of the melamine-coated particle board, and it probably weighs over 100lbs. We had to get it in my room with 2 people and a heavy duty dolly... So who knows how much a 6x2x2 cage is going to weigh.

Just keep in mind the ease of moving, as well as the ease of use. It will be a little expensive buying acrylic or glass doors to fit something that long. The 4x2x2 is 8sq feet, and will be very adequate for an adult male boa.

Here's a link I found: http://www.coolcrittersbylj.com/id133.htm

It is a custom built enclosure, and will be lighter than a wooden one. Didn't know if you wanted to spend that much, but building a 6x2x2 enclosure will cost you that much and more for the supplies. I'm pretty sure that person might build other sizes, so I would email him and ask.