Hi there! I am no guru but here is what I found in the web. Hope this help. I always wanted to have a stacked yagi on uhf too but just can't find the time to put one together. I have 2, 719B Cushcraft, works great, though never tried it stack. I need to know how to make a power divider.
With regards to buying the A430s, well why not, as long as it serves your purpose. But just wondering why not 2 meters (A144s). Try Raon in Manila, there are shops there that sells imported antenna systems.
By the way, what is your Amateur Callsign?
I missed my old antenna projects back home in Navotas City.

I use to have a homebrew 3 elements on 10 meters, 7 elements on 2 meters.
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=11183http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=2663