12 ft isn't that far, so if you want to do family shots you are going to need wide. I'd be looking at something like a 17-40 F4L to fill in below this, or maybe the new 16-35 if you think the extra stop may be of some use. I'd be expecting though that you'd be taking wide shots with plenty of DOF, so F4 isn't going to be a limiting factor so the 17-40 would be fine.
the 50/1.2 sounds excessive but i've not tried it. I still use the 50/1.8 on my 1D Mark II since the quality is quite wonderful. I'm not taking paid work though and if it mis-focusses i'm the only one who cares.
|Milky Way Rising Over Bristlecone Pine by ed rader|
from Best Photo of the Week...
|Magnificent hummingbird by fulviavecchia|
from Little Birds
|Denver Aquarium by Scott Vail|
|Hong Kong Mist by wam7|
from Fixed lens camera's