Hello, Mark.
Stuart Wilson at Maverick Models has some very nice Danish flags for the WSS period, including Colonel & Squadron flags for the unit you name.
http://www.maverick-models.com/wss_danish.htm
These look great and Stuart will do them at whatever size you like if you email him. The size quoted on the order page is actually the measurement of the flag's side on the pole, not any modelling scale. He also prints beautiful flags on cloth, too, certainly in the larger sizes.
To get "Barry-like effects" of oversized flags I use 40mm size for infantry colours (I think Barry uses 50mm), and 25mm for cavalry standards. Being time-poor & the world's worst draughtsman, I find this the best solution for me.
I can recommend checking out the other WSS countries, and he has some GNW & NYW flags, too. (His wonderful SYW flags are worth a look if you are interested in the later period). If there are historical flags you have the design of, he will usually be happy to do these for you and add them to the catalogue. This includes sensible speculative colours where there is no existing flag or data (as does Warfare with its flags).
Of course, for NYW & GNW, Warfare flags are a must have.
Some of Warfare's Grand Alliance Danish flags can be used in the later period, as even though there was a different King with a different monogram, some earlier flags were likely carried by regiments in later reigns. I plan using the Oldenburg flags for my WSS regiment in the absence of any other data, for example.
Cheers, Rohan