While cypress mulch may not be the most environmentally correct choice (because of the logging, etc.), it is a nice option for many tortoises, and if you buy it at a place like Home depot or Lowes, it can be really cheap.
It is not available everywhere, however, so if your Lowes does not have it, look at other hardwood mulches or look for orchid bark, which is really a fine grade of Douglas fir chunks. Make sure your hardwood mulch, whichever kind you use, does not have any real smell- especially a pine or cedar smell.
Reptibark and other pet shop options- main thing is cost- they are too expensive for my pocketbook!
Long-fibered sphagnum moss is beloved by many keepers, neutral to some, and disliked by others. I used it for a long time and was unhappy with how difficult it was here in Omaha to keep it slightly damp- mine was always wet or dry. I also suspect, without clinical evidence, that when wet it makes an acidic solution and contributed to the plastron rot my little guys always had. I am also not sure I want my guys on an acidic base 24/7.
I have a slightly unusual set-up compared to most in that I am using heat ropes under the substrate. For me, cypress is perfect in that it allows me to just pour in water. The 'flooded' bottom layer is heated by the cables and creates a steady flow of warm, humid air rising up. The top layer stays fairly dry, the cypress is cheap and lightweight, resists mildew, and generally works well for me.
There are lots of 'mixes' available, and without seeing and smelling the actual stuff, we won't know- but if it a rather light mix of shredded wood that only smells like soil- NO scent of pine, cedar, manure, or chemicals- then it is probably OK.