Welcome!
If you ordered the HMC and two other DVRs, you'll get a SWiM16 install, so each STB will only have one wire running to it.
Getting a 24 will only happen if you order through a third party vendor like solidsignal.com. Otherwise you'll get what the installer has on his truck. You do need to let DirecTV know that you have 3D TVs; not all DVRs are 3D capable.
When you get MRV, all three of your boxes will work together.
If you ordered the HMC and two other DVRs, you'll get a SWiM16 install, so each STB will only have one wire running to it.
Getting a 24 will only happen if you order through a third party vendor like solidsignal.com. Otherwise you'll get what the installer has on his truck. You do need to let DirecTV know that you have 3D TVs; not all DVRs are 3D capable.
When you get MRV, all three of your boxes will work together.