You will probably kill enough enderman just by finding a ominus forestIf you have BoP installed, find an Ominous Woods biome - you'll be swimming in ender pearls and string in no time.
That may certainly be a valid option to some people. This mod though is not updated to 1.6 from a cursory search. Also such a single purpose mod can be considered, as politely as I can state, uncreative. It provides a handout more than solving a problem. There's no room to be creative or build a system. There's really no challenge other than finding ore and a simple crafting to get ender pearls. Even EE3 offers more depth than that (I like EE3, but i make dyes more than anything).Install EnderOre from the Big Dig technic pack.
BoP quicksand can be your friend in nighttime desert hunts. I may or may not have trapped a dozen zombies, clad in various mekanism armor, in a carefully placed 2 block deep death trap.....