Hi Deborah
I have used a lot of suncreens(very expensive through the dermie and otherwise) and have found that Coppertone Oil free SPF 30 (which has Parsol/avobenzone-important) and Coppertone faces work quite well and have good lasting power. IThey have not been overly irritating, either.
Also, San Diego Hat Company makes some really cute/lightweight wide brim hats that help.
If you run across anything else helpful let me know!
Randlyn