For playing clawhammer banjo I get my index and middle fingernails covered with acrylic gel at a Vietnamese nail parlour in Doncaster. Costs me £6 and lasts 3 or 4 weeks with no bad effects, and is still good even after jamming all day for weeks (a recent 3 week holiday in North Carolina/Virginia). Far, far superior to the glue-on nails you can get in Boots. Easily filed down to shape with a standard nail file or Dremel tool. Been doing this for three years with no bad effects on my natural nails.
The girls who do my nails are great, as well.
Cheers
Ray