Hey grease monkey,
I'm doing about the same as you in terms of building up a streetable but hot A series - I'm using the A14 as a base with standard heads - going the twin 36 webber option.
I'm also trying to work out a cam compression, valve springs and all the specs for the build, which is how i stumbled apon this thread.
So onto your question,
Yella Terra here in aus +(613) 9555 5522
(
www.yellaterra.com.au) make roller rockers for the a-series in a variety of ratios I'm told - hope this help ya source some.
Good luck with the build