lol. happens to the best of us.
okay. slime lord is awesome. I don't know what you're talking about. unlike oozemaster, it doesn't require casting to get in, so you won't have that thorn in your side as far as IC goes. (oozemaster's other incredibly awkward prerequisites aside)
it may not give the ruinous no save con damage that oozemaster does, but its paralysis is arguably just as good. As long as you focus on your con, people shouldn't be able to make the save, at least not easily.
charming gaze is also a gaze attack, so even though your cha probably sucks, you'll be beamspamming so many people at once every time you use it (1/day/lvl!) that you'll eventually hit someone
one more advantage that slimelord gives over oozemaster is actual immunity to critical hits. while oozemaster does give light fortification, and its capstone gives a variety of ooze traits (including immunity to mind affecting, one huge advantage it has over slimelord) it never actually becomes immune to crits.
slime lord also gives you alter self at will. if you don't think that's awesome, then I don't really know what more to say.
I'd be pretty happy with either ingredient, but I'd lean slightly towards slimelord, since SIs that involve casting limit chefs' choices more.