I'd go with Red Barn custom or Spikes. I've used both (along with other LPKs) and those two are outstanding. I really liked Spikes spiral roll pins but the Red Barn custom is very good and you can get a custom kit configured exactly the way you want. The nice thing about buying a standard kit, IMO, is that you have spares of everything you upgrade. There's a lot to be said for spares....
An interesting side note that probably isn't relevant to you since you'll undoubtedly not use a stock milspec trigger:
I bought a PSA MOE premium LPK for my Dissy build. It was a great LPK, but the most interesting thing is that the standard trigger in that kit is, by far, the nicest standard mil spec trigger I've encountered. With respect to creep, pull, feel, etc, it's performs almost exactly the same as my ALG ACT. Handed both blindfolded, I'd be hard pressed to tell the apart by feel. I kinda doubt all PSA triggers are like that, but I certainly got a sweet one with that kit. I have zero intention of replacing that dissy trigger....ever.