I personally wouldn't worry too much about riding on them as your working on getting the replacements. Maybe don't hop any curbs. There are a wide variety of replacement wheels that could work for you, just make sure the rim and hub dimensions are all the same. Since its friction you have more leeway with your freewheel options, but some aren't compatible so make sure to figure out what will work with the rest of your drivetrain. You could get new rims and try your hand at re-lacing them onto the existing hubs, but I'd just get a new wheelset that checks all the boxes. +1 for the Sun cr-18