Windows RDC can be used if both the computers are on same network. As your work and home computers are on different networks, you can use remote support tools such as gosupportnow in order to remotely access your home computer from anywhere. It is very easy to use and costs only $19.95 / month.
It appears video conferencing vendors such as Polycom best meet your needs because of exclusive video conferencing requirement. If you are looking to have web-video conferencing as well, then what I suggest is to deploy on premise web-video conferencing appliance such as RHUB appliances.