TvT seems an awesome idea but it is a fail idea. You expect ppl of opposite faction to come along and stand by each other so that a pp can fight one another while others watch?. In a pvp map RED=KILLS. Only GM can/should try to make TvT. You guys are GSes i believe, therefore make a event that can be carried out without much obstacles. GVG/1V1.
1V1 = Best 2 out 3 wins gets you through to the next round. Top winner from each faction will battle one anther in arena. Battle should be whoever kills the other guy 5times Wins and is declared the top 1v1er for that week/month. Should be an on going event
GVG = Apulune/Iris. GVG is exactly like pvp expect you are representing your guild but IS/PS/DF/POG/UT etc any skill that will prolong the GVG should be restricted. Also remember to put restrictions on # of participants taking part as not to give one guild too much advantage. Example in gaia we had GVG, DDvPaW 30s GvGers from each guild coming forth to take part. One of the most exciting and memorable Event i had ever took part in.
In short make an Event that will leave a good impression about shaiya not one that will result in total choas.