I think the Case Logic DSLR Camera Holster TBC-406 would work great! I have handled the SX50 several times, so I know its size. This bag would be very nice for that camera and has lots of extra compartments for more storage. It's also top loading.
We own the bag. It easily houses a Canon G15, with the filter adapter tube and filter with lens cap all attached. with plenty of room to spare.
Although, I imagine that you have probably found a suitable case in the last six months yourself... :)