You may need to wait until Forge is bukkit compatible again. I haven't found any good forge based block protection mods.
UPDATE: Eeeh... looks like Forge <3 Bukkit won't happen. So let me rephrase: You may need to wait until Forge has added some APIs so that bukkit mods can be ported to Forge.
There are some awesome ones for bukkit (my personal favorite is
http://www.curse.com/server-mods/minecraft/grief-prevention)... however you'll probably have to massage it to get it to work right. A lot of the cool mods required op level access in bukkit in order to work properly which tended to bypass grief prevention.
That's why some lazy tekkit servers disable things like quarries, turtles, etc since they wouldn't play nice with the block protection mods.
Another option might be to check out the Forestry Trade Station... I think it has built in block protection. I haven't tested it myself on SMP though so don't quote me on that.