Steve,
I've done a bit of research on this lately. My only comment would be to make sure that whatever strobe power supply you buy flashes at a rate that meets the aviation standard. I seem to recall reading somewhere, maybe here on VAF, that anti-collision lights should flash between 40 and 100 flashes per minute (don't quote me on those numbers). The problem is that many of the non-aviation (emergency vehicle) strobe power supplies flash at higher rates (~140 per min). I am talking about the flash rate, not the flash pattern. It is my understanding that many units have adjustable patterns, but not rates. I am not sure if the Whelen unit you linked to is one of their aviation units or their emergency vehicle models.
FWIW, I ended up buying a XPAK-604HR power supply for this exact reason. The "HR" stands for half rate, where the flash rate has been slowed to meet our flying needs. I bought it from a private party, and ACS sells it as part of a strobe/nav kit, but I think the only place to get it by itself is
GS-Air. I haven't tested mine yet, so take my comments any way you like.
Good luck!