personally i built all my config upon toolmanager because of the number of games (around 700). i splitted them according to their type (arcade, stratedy,adventure....), so that when i select a type from the menu a whole table of games appear (text only so that i can display around 80 games on 1 screen, graphics would have made it hard to follow...). on paper, i printed all manuals, covers and tests i found on lsd disks, exotica website, or abandonware magazines website...a whole library!!!
this way i can select a game from the pretty nice info/gfx available in the library, and just launch it in a simple click from my toolmanager interface.
i just have a basic config :A1200, 8M fast and 2Go HD and it really works fine. i don't think toolmanager consume that lot of memory..all my games are working with preload option (even games with lots of disk images : dragons lair series, hugo....)