Reminds me of when I had Twilight Forest and Gregtech; I'd always take my trove of Lapis and make a massive LESU.
I guess since you're 1.6.4 you're not able to us experimental Gregtech or IC2, which is unfortunate. Gregtech's recent versions start off HEAVILY relying on Bronze. Furthermore, GT adds Bronze Fluid Pipes; you would have an easy time making a steam-driven setup like I'm using myself.
If I'm wrong, 1.6.4 ~= 1.6.2 and they work:
http://ic2.player.to:8080/job/IC2_experimental/
https://dl.dropbox.com/u/88825306/Mods/gregtechmod.zip
However, note that IC2x has redone the power system, making Tin Cables be 32 EU/t, Copper 128 EU/t, so on, and CESU's are the MV storage, MFE's are now HV, MFSU's EV. Brave new world!
Going in a different direction, there are tools and such that allow you to regenerate ores, including retroactively and without damaging the gameworld or any player alterations. Unfortunately I haven't had access to my remote server recently and I've forgotten the name of this particular one from lack of use...