I have a map built in the Coliseum that I would like to have tested. Here are some screenshots. Somewhat of an overview Blue base Red base Center platform Under Center platform Oh yeah the gametypes supported are Slayer,FFA,Neutral Assault,One bomb assault,multi flag,neutral flag, one flag,king of the hill,oddball,and stockpile. link to Download Bungie.net : Reach : Player File Share
You would have more luck finding testers if you posted it in the Testers Guild. There it will be tested and you will receive detailed feedback.