Everything I did for 1.8 is basically deprecated and I can't recommend fooling with anymore. There was
FMC, which was basically a total MCP replacement, with custom mappings. I did that right as 1.8 was coming out, then updated it all to 1.8.1. The problem is just that: it used its own mappings, which made porting mods hard. I also never released the API I started making to work with it since it was nowhere near finished when I decided it all just wasn't practical. Since then I've declared the mappings fair-game for anyone who might actually want them.
I then later created a wrapper to download MCP itself, modify it, and create a dev environment for FyPI, which I made quite a bit of progress with. I got some stuff like Iron Chests and my mods like Hopper Ducts to work on it. I just never released it since it wasn't in a state that I felt was fully usable, then 1.9 snapshots started and I realized there was literally no point to wasting any more time on 1.8 when 1.9 was actually more enjoyable to play.
So over the last few months I've been recycling some of the code from both of those projects for
Meddle and MeddleAPI, directed at 1.9. There's over a dozen small mods there, and they depend on a related project called DynamicMappings in order for me to quickly stay up to date with each snapshot release. Though I spend so much time trying to add mapping detection routines that the API itself is still rather limited compared to what I've had in the past. But once the mappings are there, I can bring more code over.