WAAS (Wide Area Augmentation System) has nothing to do with this topic. WAAS is a supplementary signal broadcast alongside GPS signals, containing position correction information. GPS/WAAS is expected to provide the means by which Cat 1 precision approaches by GPS might be acheived.
Chiglet... I assume that your intention is to fly outside controlled airspace. In that instance your plan shouldn't really get the Brussels treatment and the software on the Eurocontrol site is not intended for use with that kind of FPL.
If you want to know which route you should file to make CFMU happy, what you need is the Route Availability Document. It has a whole website of its own
http://www.cfmu.eurocontrol.be/rad/
Extracts of this are contained in Jepps and Aerads.
2D