nitefiter : for your info 290 is an RVSM level so it will be 250-270 easbound....
and at 250 on an RJ or an Embrajet is not so nice....
For the others on GPS : not only GPS is not necessary for RVSM but you do not even need to carry the GMU suitcase ( GPS Monitoring Unit) to get approval : just overfly one of the HMU a couple of time using your good old VOR and if your altimetry is according what your mode C says, you,re on ( providing you carry the additional hardware as mentiooned already )