A with-it L.A. couple scrambles to avoid being without it in the sharply witty The New Age. Peter Weller and Judy Davis play the Witners, a trendy twosome with more dollars than sense as they careen along a downhill path of mad business pursuits, sexual escapades, new-age babble and questionable spiritualism. In a glitzy society where everyone's born to shop, the Witners are starting to drop