Definately use the rigid. You can get it in large sheets and glue it to the wall. That would help to start. Also the rigid stands up to moisture better. If you wanted you could then put up 2 x 4's and sheetrock.
2" rigid foam will give you an R10 to R12.5 depending on the product you get you can also get it with a tounge and grove to lock together better.
Use kraft faced batts for the ceiling