Brewing supply shops online sell a nipple that you can use to daisy chain the two regulators. I believe you remove the pressure gauge off the first regulator, install the nipple, install the second regulator to the nipple, then install the gauge on the second regulator. I'm thinking about adding a second to mine too.
If your takin' your girlfriend out tonight
You better park the car well out of sight
'Cos if they catch you in the back seat trying to pick her locks
They're gonna send you back to mother in a cardboard box !