Yes, there are tubes that are matches for the BT-60. However, I've only ever found them in kits already (or a parts assortment), and they are consistently cut to around 5". That said, I've managed to make an entire upscaled clone of a rocket (my Clearokee D) using the florescent light guard mentioned above. I've also used it to make a payload section for a BT-60 upscale of the Estes Supernova, and my take on the Wildman Darkstar.
To get a BT-60 nose cone to fit a light guard, I find it best to use a scrap of BT-60 to act as a shim. I also add a small stand off (a piece of a wooden coffee stir stick) to help the launch rod clear the additional thickness.
Yes, K'Tesh linked to the Estes assortment that contains 'em in his post. They're short - four or five inches tops. I'd forgotten about this set when I posted previously.
Sometimes they can be had from Estes but I haven't used one of theirs (outside of a kit) in many years.
As others have mentioned there are T-8 and T-12 Lamp covers in 4ft and 8ft sections that are a touch larger then BT-50 and BT-55 tubes.
There is also a Pretty extensive selection of Clear Polyethylene and Polycarbonate Mailing tubes available for the industrial supply and packaging stores.
Most do not directly fit our model body tube sizes but MANY are easily adapted to use with our tubes and standard Transitions and Nosecones.
FYI the 2.55 ID section is as close to a BT-80 Tube section dimension as you'll likely get. I use this one often in Upscale.