I think he'll be very good, actually XD He's a nurturer, and will probably forget to even sleep when there are kidlets to look after. He's more likely to throw practicalities out the window for the sake of the kids than he is to neglect them, ie assuming they can somehow afford the best of everything for them.

Canon update rofl. Even then, he's due for the rage part of grieving sometime soon, which for Jim will translate into manic smiling while committing acts of mayhem.