Package it for a distribution, not as a distribution.
In other words, 90% of the recent article (about compiling and installing rpcemu) goes away as people just pick the 'rpcemu' package from the repository of available programs.
Whilst bundling rpcemu with a distribution to create a RISC OS machine crops up as an idea every so often, I'm not sure it's actually that useful? People seem to like the advantages that the host OS can bring, a browser that doesn't suck, for example. So running the two OSs alongside each other seems preferable to deliberatly hiding the host OS for the sake of nostalgic purity.