If there's a bike co-op in your area, use their tools for a while and see what you'd like to have at home. And learn the skills to use the tools.

A set of T-handle Allen wrenches with ball end would be nice. You've already found the limits of the triple Allens, it sounds like.

If you plan on servicing cup-and-cone hubs, you'll need some cone wrenches. A set of 8 to 17 mm combination wrenches is a must. Chain break too. Cable cutter.

A parts tray like a small cake pan is nice. So is a magnetic parts dish. A dog dish is nice for washing small parts. Be sure your shop area has safe oily rag disposal.

DItto the above, get the specific bottom bracket and cassette tools for the bike(s) you and your family have.