I see a lot of multi-class questions and builds and advice up, but I haven't seen this one yet. (To be honest I didn't search for it though.
Rogue/ Cleric.
My initial plan (based on 10 minutes of careful thought under the influence of a dose of cold medicine) is to go 15/ 5 for the level 3 spells. (Prayer and others.) Doing 17/3 would work as well for the buffs. I need to remember to check the healing spells on level 3 before I go for cleric 5 though.
Get extend spell of course.
I'm not worried about min/maxing, it just seems fun to play and better survivablity than a solo rogue.
Of course I'm zoned out on cold meds at the moment so feel free to tell me what's wrong with this idea. ;-)