the need to use video conferencing should be considered as a factor for upgrading your call managers to at least 4.1.
many enhancements, fixes and features, especially for video conferencing, have been introduced since 3.3.
if you required vidConf with 3.3, you should consider using a polycom solution.
http://polycom.com/products_services/1,1443,pw-35,00.html
the VSX series is pretty nice with straight forward config/administration and of course, superb polycom technology/support.
(may not be the cheapest solution but it's definately stable and works well)
NOTE: the cisco IP Video Phones, 7985G, may be able to fulfill your needs; especially if vidConf is only intraCompany.
(requires 7985 phones, ccm 4.1+ and a cisco MCU)
