Sonic Retro has a huge slew of things for you to check, and they make modded ROMs available for download.
Just two downsides: First, you can't contact them on Retro if you're not a member. Second, you won't be accepted there unless you can hack ROMs (and trust me, they rarely use complete editors, they can go as far as hexadecimal modding).
For Retro members in other communities for you to contact, Stealth and Taxman (Christian Whitehead) have Twitter accounts, E-122 Psi can be seen on SEGA forums, and Lake Feperd is likely seen at Sonic United (which is in maintenance and reconstruction at this moment).