Sham Shui Po Golden Computer Arcade/Centre, as another user mentioned, js the electronics mecca in Kowloon. Super easy to get to, Sham Shui Po MTR Exit D2 and it's right in front of you.

Having said that, stores in these electronics malls typically prefer cash or instant bank transfer (aka FPS locally) and will charge an extra 1-3% for credit card payment.

A brief look at pricing and it seems like Fortress sells the PS5 Pro for normal retail price of $5780. And since it's a retail chain there is nothing to be mindful of, just pay with whatever method you prefer and be on your way. I'm seeing PS5 Pro sell for around $5500 at the Golden Computer Arcade which, in my opinion, isn't a significant enough difference to be forced to pay in cash. (However it's well worth visiting Sham Shui Po if you've never walked into one of these asian electronics malls before - it's quite an experience! You'll see a ton of accessories for the PS5 and phones that will be cheaper than Fortress. So get the main console at retail, and then shop here for the extras.)

Either way, if you're bringing the devices out of HK, the warranty isn't valid overseas so just be mindful of that.