I want to mount some SMD leds upside down so that the light shines through the PCB. So this requires the LEDs to be completely flat and have part of the contacts be on the top side as well. Is there an easy way to find something like this besides wading through pages of LEDs in mouser?

 

OSRAM has bottom entry SMD LEDs.
For example:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=475-2507-1-ND

Search for OSRAM TOPLED