I have a couple of server ideas for the European servers although no worries if used for the U.S servers.
First one is my own map (Pd_2fort) i call the mode (team death money) the reason i choose 2fort was because its a map everyone knows and is a working prototype.
when the (player destruction) game mode was introduced into TF2 is opened up possibilities for a death match style mode.. so that's exactly what this map is.
when you kill an opponent they drop money (like in MVM) and the first team to collect the set amount wins (hense team deathmatch). not only that. this map would be an exclusive for BlackWonder, and i can make other maps in the same style if popular.
here's the link >
http://www.mediafire.com/file/dsh95l12cggdm9d/pd_2fort.rar
Second suggestion is that since the matchmaking update rd_asteroid has vanished from TF2 including casual mode, there's only currently one server in Europe i believe that even hosts rd_asteroid.. perhaps BlackWonder could take advantage of its rarity.
Third suggestion is the first ever Custom map for TF2 (Lazytown) there's only 2 servers that host this classic community map in Europe atm and its notoriety for long hard to win games is Legendary.
best quality version here >
http://www.mediafire.com/file/8jozb3jyzyes33o/cp_lazynewtown_rc1.rar
Fourth and final suggestion (for now). is cp_warpath there's so many different versions including seasonal maps, this map again is the stuff of legends for long battles and hard to win matches.