do u mean using the AEC objects (or other VIZ only functions) in max? there is someways to achieve but i think u better wait for max6 which will include the functions in viz. And viz4 is the last version of viz as far as I know. just forget it..... it will only appear as a so-called "viz renderer" for use together with autodesk architectural desktop (ADT).
If u means 3rd party plugins for viz/max, u can visit:
http://www.digimation.com
http://www.turbosquid.com