Manapunk has always been my dream setting. But no DnD sacred cows! No standard fantasy tropes!
Thus I would take d20 Modern with a Skill Base magic system (likely EOM: Mythic Earth) + d20 Future rules for mutations (for manna mutants) and cyberware (for Golemgrafts)+ Grafts from Lords of Madness etc.+Eberron dragonshards and resultant tech (possibly in combo with at least the flavor of Iron Kingdoms mechanika but not the rules)+ Grim Tales to add in some fantasy Talents and Feats from 3.5 + my own golemtech rules.
Along with that I need non-standard races (likely do it myself).
I want:
An Insect race - which I have some interesting ideas for already, and the mechanics I think I need.
A Plant Race - again I have some ideas, some possibility but nothing solid yet.
A Construct Race - maybe warforged, maybe Ironborn, maybe soemthign else.
An amphibious race - lizard like or frog like I don't know.
An avain race - maybe the one from Races of the Wild.
Humans.
Mutants.
Lovecraftian horrors+evil corporations vs. ancient noble orders reduced to the level of street gangs and cults. I want stark evil but I want the heros to have a noble and powerful good that drives them to seek change.