I'm afraid there are some misapprehensions here.
From 1994 onwards, all hardtail Konas were designed to give a 71 degree head angle with a 41cm a-c rigid fork.
This means there is no difference between the different years in terms of what fork you can use. A 1999 frame is exactly the same shape as a 1994, as indeed is a 2009 frame.
I appreciate that it's natural to think that as forks had longer travel over the years, Kona must have changed the geometry to accommodate them, but they didn't. Some companies did do that, but Kona kept the frames the same and simply fitted shorter stems to keep the steering the same.
Prior to 1994, Kona frames were made for a 39cm a-c rigid fork, which makes them less suitable for fitting suspension to - not impossible though, but perhaps best to stick to short-travel forks, and again to use a shorter stem to compensate for the longer fork.
Kona have never had such a high reputation for their aluminium frames as for the steel ones. I can't see any logical reason for that. The Kula/AA/Pahoehoe used top quality Easton tubesets, the best you could get, and the geometry was exactly the same as the steel frames. I think it's really just a market perception, the upside of which is that Kulas are really cheap to buy.