Saebel's patch is unfinished: http://www.gamesas.com/topic/1465086-relz-oco-rbp-integration-patch/page-1
there is also an already compatible patch if you are willing to use OCO v1.
I use both already without a patch and haven't noticed any problems. Though I am using the no gameplay changes version of Integration if that makes a difference.
You can play without a patch, the only problem is NPCs of new races - they still look potato-faced like non-OCO ones.
Integration was a primary factor with me doing a fresh install of Oblivion. Didn't really care for the look of OCO2 but after eight years I wanted something other than Natural Faces. Decided to use TNR instead. Glad I did. It's more my style.
That said, I am running OOO + Shivering Isles + RBP/LAME/Integration and this is not posing any problems in my current game. On top of that I'm also using MOO and of course bashed patched. Like I said it's working OK for me except with both OOO and MOO I'm being mobbed by large groups of bandits, marauders, etc. And they don't come at you one or two at a time. It's like they yell out "there he is, get him" and they all come charging at once.
Now for Integration's faces, they are bad, bad, bad, I decided on using Integration Alternate NPC Faces by LazyMonk. Much better. If they work with the light version I would suggest giving them a look.