I'll second the Custom 5 and Norton, although the Norton -while a better pick-up in most senses- has a slightly leaner, but tighter low end than the JB.
Here's another option: DiMarzio AT-1.
Has more thickness and roundness than the Norton, while also having that 'JB but better ' core thingy going on.
Originally Timmons' Ibanez sig guitar had a JB IIRC, so it makes sense that his sig pickup is based on that.
I replaced a Norton in a Les Paul with the AT-1, looking for a bit more thickness in the lows and low kids and it delivered.