Akumar,
Do you want to run all 3 on one PC? If yes, are you doing sweeps or I/Q streaming?
If just sweeps, I think a standard desktop PC with an Intel i7 processor would work fine assuming it has enough USB type A ports.
If you need to perform streaming I/Q then you will need to either use more than 1 PC, or add PCIE to USB adapter cards. The reason is that when I/Q streaming, most USB 3.0 host controllers can support at most 2 BB60 I/Q streams. Most PCs only have 1 host controller who’s bandwidth is shared between all ports. Adding a USB 3.0 to PCIE adapter card will add more host controllers with their own 5Gb/s link. You would distribute the BB60’s accordingly. Additionally the PC would need to have adequate performance to be able to maintain 3 I/Q streams, which a quad core i7 or higher would likely be capable.
Let me know if you have follow up questions.
Andrew