I recently stumbled across a post on the Tekkit forums for a plugin called BukkitForge; in the description for how to set up a Bukkit Tekkit server I realized it was compatible for all Forge based mods and I tried it on FTB and it works with little to no errors. I am now running my server with plugins on the latest version of FTB. Enjoy.
If link is broken: Here
If your server lags you can add these Java extensions to help reduce lag. You need to add these in your Startserver.bat on the same line after mindcrack.jar.
-XX:+UseConcMarkSweepGC -XX:+CMSIncrementalPacing -XX:+AggressiveOpts -XX:UseSSE=4 -XX:+UseFastAccessorMethods -XX:CMSFullGCsBeforeCompaction=1 -XX:+CMSParallelRemarkEnabled -XX:+UseCMSCompactAtFullCollection -XX:+UseParNewGC -XX:+DisableExplicitGC -XXarallelGCThreads=4
The only thing you might need to change is the amount of RAM and -XXarallelGCThreads=4 (change 4 to however many CPU cores you have on your processor).
If link is broken: Here
If your server lags you can add these Java extensions to help reduce lag. You need to add these in your Startserver.bat on the same line after mindcrack.jar.
-XX:+UseConcMarkSweepGC -XX:+CMSIncrementalPacing -XX:+AggressiveOpts -XX:UseSSE=4 -XX:+UseFastAccessorMethods -XX:CMSFullGCsBeforeCompaction=1 -XX:+CMSParallelRemarkEnabled -XX:+UseCMSCompactAtFullCollection -XX:+UseParNewGC -XX:+DisableExplicitGC -XXarallelGCThreads=4
The only thing you might need to change is the amount of RAM and -XXarallelGCThreads=4 (change 4 to however many CPU cores you have on your processor).