Which “private blockchain” would you use? (evm-comp only?)

I've been hired by a company to "add crypto" to their current (successful) product, but they want to have it on a "private blockchain"

The team's initial thought was to fork geth (POW), though I see there being a high cost to maintain/run this.

I was hoping that there was a good POS substitution available.

I'd prefer an EVM protocol, though I could possibly be talked into a diff lang.

What does Reddit think?

What would Reddit do?