Since both developers are proprietary you're not going to get exact formulas. However the published MSDS's compare favorably for the main ingredients. Both use Dimezone-S and hydroquinone as the developing agents with sodium carbonate for the alkali. The pH values are also comparable. Ilfosol also uses ascorbic acid and is therefore a bit more environmently friendly. I think the two are a good match but you might find a better one with some searching.
Check the following links.