You are correct that for multiple parties to be in a video conference, you will need either an MCU or a TelePresence Server.
There are some small differences between a MCU and a TelePresence Server in terms of functionality - see what-difference-between-mcu-cisco-telepresence-server for a quick comparison.
It has been discussed a number of times before that the MCUs are no longer receiving any further Product Development and the TelePresence Server is the way to go in the longer term - this may help sway your decision one way or the other.
Note: Your question would be better placed in the TelePresence section of the forums where these devices are more actively discussed than in the Other Collaboration section you've posted in - I'd suggest, if the above hasn't answered your query, that you move your discussion over there.
Wayne
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Wayne
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