30 lb building paper is what used to be called 15 lb building paper. I would avoid using the term "tar paper" because although it is illegal to use coal tar, some Chinese building papers have been found to have coal tar in them. Any specification should make it clear that any coal tar content is not acceptable.

I would avoid the use of any kind of asphalt impregnated or coated paper if it isn't going to be supported by sheathing panels because it tears too easily and would require blocking at the horizontal joints. A high quality non-woven non-perforated house wrap like Tyvek or Typar would be better if the horizontal joints occurred over floor framing or blocking. DuPont Commercial Wrap would be an even better material since it is extremely difficult to tear. But I would add sheathing and a weather barrier or the Zip system from Huber. However a lot depends on the detailing of terminations at the windows, doors, soffits, etc.

It is easier to get a uniform pale grey color with white cedar and white cedar is cheaper than red. For the beach I would consider the highest grade 15" white cedar factory dipped in Cabot's bleaching oil. I would use red if the shingles were going to left unfinished.

Thanks, Renovator. I appreciate your comments.