I've tried quite a few huds and found that ToonHud (
http://toonhud.com/) is the most surround friendly. It certainly isn't perfect (menus appear on the outer monitors), but in-game most of the information that the default hud pushes to the sides is on the middle monitor.
For the previous (September) release of ToonHud I did have a fiddle with positions of chat and kill-feed, but those have been lost since the October Halloween update. Fairly sure that TH doesn't provide a mechanism for me to alter file level elements unfortunately.
My 'sort of' eyefinity hud :
http://toonhud.com/user/eyefinity/theme/Q0MZO5GI/Ever joined a game of TF2 when it's already started and have the 'metal doors' on your side monitors? Type "hud_reloadscheme" into your console to make them go away.
Cheers