What should I get?

[LauraAMayer]

Which one should I get? My computers are so slow. I don't know whether to get the RBK44 System or the AX6000. Right now all I have is a ViaSat modem/router, and I am worried about security and getting hacked.

[LauraAMayer]

I don't understand any of those answers. They did not answer the question I asked.

[FURRYe38]

Ether one. 

The Orbi AX is for AX supporting devices. If you don't have any then either get the RBK44 system or you can future proof with Orbi AX. Also there maybe a cost difference. 

If you have a modem router already, and add a Orbi system, This would be a double NAT (two router) condition which isn't recommended. https://kb.netgear.com/30186/What-is-Double-NAT
https://kb.netgear.com/30187/How-to-fix-issues-with-Double-NAT
Couple of options,
1. Configure the modem for transparent bridge or modem only mode. Then use the Orbi router in router mode. You'll need to contact the ISP for help and information in regards to the modem being bridged correctly.
2. If you can't bridge the modem, disable ALL wifi radios on the modem, configure the modems DMZ/ExposedHost or IP Pass-Through for the IP address the Orbi router gets from the modem. Then you can use the Orbi router in Router mode.
3. Or disable all wifi radios on the modem and connect the Orbi router to the modem, configure AP mode on the Orbi router. https://kb.netgear.com/31218/How-do-I-configure-my-Orbi-router-to-act-as-an-access-point and https://www.youtube.com/watch?v=H7LOcJ8GdDo&app=desktop 

Good Luck.