If you need to do a trade, use one of these people:
Official: (Staff of MPGH)
Dave84311 (99% won't do it)
arunforce (99% won't do it)
iverson954360 (Usually will do)
ace76543 (Usually will do)
Beer_Hunter (Usually will do)
Jeremy
Hispiforce
Obama
Czar
Unofficial: (People who have rep, but not staff)
imsohoooood
If you want to be a middle man, you should have over 750 posts.