Jan
have you tried giving the original cyanotype a chance ?
It will produce rich blues and a full range of tones so easily that I find
it difficult to understand how some people fail to do so.Just expose until
all the high middle and highlightr tones have reversed and everything else
is dark blue except the parts of the inmage that are intended to print
white which should remain green.
As to negatives, as you suggest, Epson coated paper negarives produce
results that are almost indistinguishable from prints made using film.
terry king