Sorry gthumbs, I misread your first post and thought it said you have mold on everything.
All orchid growers have their favorite mixes and it just depends on what works for you. You will find many discussions and downright arguments on this forum regarding which is the best one to use, but all of our situations are different. I lived in SC for 4 years and know how humid it is there in summer.
If your bark is staying wet on top all the time, it may be holding too much moisture for your conditions.
The mix I am using (see discussion link) can be a bit pricey if you have a lot of plants. What I know is I lost many phals using bark and haven't lost a single one since potting in Aussie Gold. I grow indoor phals and outdoor cyms with no rotten roots, lots of new growth of roots and leaves.
Congrats on your great find at Lowe's!! YesYesYes definately re-pot them into what ever mix you decide on. Cut off the old spikes and trim any old, rotten roots before re-potting. (some is normal) Very often orchids from DIU stores need some TLC because they really don't know how to care for them.
Good Luck with your new babies!
Ask lots of questions; the learning never stops.
White stuff on soil