Mosaic, Equinox, Azacca, Triple Pearl, Cashmere, and Lemon Drop are all newer hop varieties that I like alot. Mosaic, Equinox and Cashmere are well suited to IPAs, where Azacca, Triple Pearl and Lemon Drop work best for APA IMO. As for blending, it depends on what you're after - most all of these are fairly fruity hops, so could be blended with something like Simcoe,Chinook or Columbus for some piney balance, or blended with other fruity hops like Citra or El Dorado for a 'fruit bomb' hop character. I like Equinox the best of all these.
EDIT - And blending any of these with traditional citrusy hops like Cascade, Amarillo, or Centennial is always an option, too. You just have to decide what kind of hop character you're after. And the rules aren't rigid for the APA vs IPA recommendations - Azacca and Lemon Drop are used in a few commercial IPAs as well, for example.