I agree with Lee Ann and Kristin. The bathroom is the only place I ever have an issue with preferring a certain length of tubing. With my 43", I always have plenty of slack to pull the pants down with the pump clipped to the waistband. I’m so used to years and years of that length that I sometimes pull the 23"s a little hard and feel a bit of a tug when I wear them. But honestly, either is fine. From my experience here at TuD, I’d say most people trend toward the shorter. I’ve just always used the longer.
I can’t see a need for the tubeguard, but I’m a gadget enthusiast, so I can’t see harm in trying it later if you’re intrigued by it. Like everyone else mentioned, I just shove the tubing inside my underwear and don’t think about it after that.
Cindy’s right. Ask them to send you different lengths to try. All three of the companies I’ve ordered sets from have always been happy to do so.