Marchbirdy - I am with the others on this I'm sorry. Never consider extensions acrylic or otherwise. I would probably suggest going to a better manicurist who will buff your ridges with a special buffer type file. They really do work. Put cuticle cream or oil on every day without fail and massage into your nails and cuticles. I think short well manicured nails are so much nicer than falsies. Acrylics and the like are a bit Waggish if you know what I mean.
Sorry this is not the answer you wanted.