I am looking for a router which will provide access controls, defined per
local computer LAN IP, to block access to all websites except for those with
an established permit rule. All the routers I have found have only block
rules, which in the context of the Internet are pretty much useless.

My current router, a Microsoft MN-700, allows this. I can set up a rule to
either block or permit web domains for specific LAN IP addresses. So, for my
kids computers only, at the router, I block all web domains and permit only
a few required ones (i.e. microsoft.com - for Windows updates, mcafee.com -
for AV updates, apple.com - for iTunes, etc.). The kids are allowed to surf
the Internet (i.e. Google, etc.) only from a centrally located family
computer. The problem is that I recently updated the McAfee AV on all the
computers in my house and the MN-700 is hanging whenever the McAfee on the
kids computers does an update. I suspect there is a bug in the MN-700
filtering software, that the McAfee update is triggering, and there are no
newer firmware updates for the MN-700. So, my next best option is to replace
the MN-700, which is quite old now and should probably be replaced anyway.

Problem is, I can't find a new router with the same web permit/block filter
rules as the MN-700.

Anyone have suggestions?