There are really only two supported ways to make RPMs (not counting manually creating the spec file, etc.). cpanspec (see your first link) and cpantorpm. cpanspec is good, but has some problems (it hardcodes some redhat specific stuff, and it tries to parse the Makefile.PL/Build.PL files which is fine if they follow strict conventions, but I didn't like that assumption), so I wrote cpantorpm. You can read more details about why I wrote it here
. Have you tried to use it? It's got a lot of options, but if you have any questions, feel free to toss them out and I'll try to respond. It'll do everything that cpanspec and cpan2rpm (an older tool which hasn't gotten much support in a long time) will do, doesn't care what rpm based distribution you're on (I use it on both OpenSuSE and Redhat), and I've built hundreds of RPMs with it.