Look up TekkitCustomizer Plugin. It helps a lot with tekkit, since none of the RM or DM tools create a block break event. This plugin forces them to do a block break event, which means they are picked up by normal grief prevention tools, as well you can customizer most of the commonly exploited items. Also, if it it tekkit classic, ban deployers. They sound harmless, but if you put REP into them to try and make fireworks, it crashes the server and corrupts several chunks around the device, making it impossible to break outside of MCedit.
All of this knowledge is from personal experience, I used to run a tekkit server that ran for almost a year and became ungriefable.
