LUA support (prefferably GUA aswell) - Heartstone / ArcEmu
VMap support - MaNGOS / Trinity (Ascent based have lot problems with this from what i've read, crashes bugs etc)
Core being worked on/Updated for patches - MaNGOS / Trinity / Heartstone
Stable with 100 players - MaNGOS / Trinity / Heartstone (You have to have knowledge of which rev to take though) And Arcemu, but that's currently for patch 3.0.9
3.1.3 support - MaNGOS / Trinity / Hearstone
Good tools for DB Editing, like Quice, changing Zones from PvP to Sanctuary, etc. - MaNGOS / Trinity / Heartstone / Arcemu - eg all of em, you just have to know how to read and _MOST IMPORTANT_ Stop using repacks.
Capacity for more than 100 players. - All of them are able to handle more than 100 players.
Communities where I can get some help. -
getmangos.com > Home ,
Trinity Core MMo Server Framework - Powered by vBulletin ,
AspireDev Forums - Powered by vBulletin Welcome to ArcEmu :: The home of the #1 MMORPG Emulator!
For my personal opinions, for blizzlike server where you pvp / pve alot, i would suggest using either MaNGOS / Trinity, as the amount of things working / alot smaller amount of bugs compared to the two is very big.
But, none of them support Lua, which i do not see as a problem since you have c++ & EventAI scripting ability (Scripting in DB, eg SQL)