[SR-Users] Commercial SBC or Kamailio

We are trying to setup VOIP infrastructure, mainly wholesale and retail.

What is best option if money is not the problem?

Developing our own infrastructure using Kamailio and other open source packages to act as SBC and switch or buy a commercial solution like GenBand/Sonus/Sansay.

We are looking for high performance with scalability to handle thousands of call setups per second over the period of few years.

I have no idea on how/if can kamailio outperform commercial solutions or not.

Advantage of using kamailio is flexibility and possibility of customization as per requirement,

I am new to this list so please advise if this is not a valid question to be asked here.