WSAD and RAD tests are pretty similar.
Honestly...I think a tool certification in your toolkit looks really good. Your Sun certs are all language based. A tool certification looks really good.
Want a hint?
Test 255 is very heavily tool based, so you need to know the various wizards pretty good. But IBM test 256 is very Servlet/JSP based, with a bit of EJB stuff thrown in. If you got the Sun Web Certification, you'd probably find the exam quite easy.
Good luck!
-Cameron McKenzie