I've used CRM, never used the other two.
Five9 appears to have an native integration with CRM so you should be good there.
Five9 Application Integration
And, Etriuge also appears to have a native integration with CRM.
Stand Alone or Integrated with CRM
CRM doesnt have native integrations to either of those. But CRM as a product has a huge number of extensibility points and can pretty much be integrated to anything with another effort.
No idea if Five9 and Etriuge could speak to each other, though looks like you might be able to achieve communication through CRM.
So probably achievable, but worth investigating further to see how 'easy' it actually is, and what the native integrations actually provide.