As has been said, 'mountain shock' indicates that the bike was designed for suspension - it was the last of the Explosifs to be conceived as a poor man's xc racing bike (the team used King Kahunas), and nobody that was racing to win was on rigid forks by 1997.
It seems almost comical to us now that it was sold with an Indy SL fork, but at the point when that was specified the Indy wasn't yet on the market, so maybe it wasn't clear to Kona that it flexed like spaghetti. And after all, an Indy SL did retail for £299, believe it or not.
I think most 97 Explosifs that were raced would have been equipped with a 97 Judy SL in Judy yellow and that would suit the colour of the frame fairly well. However I think the ideal fork would be a 97/98 SID, as even those original ones were much better forks than the Judy and the blue looks good with the fairly similar blue of the decals. An alternative would be the 98 Z2 in silver blue, heavier, stiffer, works better.
It was designed for silver parts and silver looks more retro, but IMPO black looks just as good. But my other personal opinion is that you shouldn't mix black with silver.