THE best places to find eth weapon bases are racks in 1.07 Lower Kurast. It's because eth 1.07 version gets bonus +50% max ed. It is also the closest to "ebugging" a weapon you can get. Note: you cant get bows from 1.07 racks
Eth 1.07 armors are useless for any RWs that have "%ed" in them (different math when ebugging). Still, the best place to get non-eth armors is 1.07 LK (I have my perf sup 15%ed AP from 1.07 rack).
All other stuff = 1.13 pits (the Pit, Ancient Tunnel, Mausoleum) or Hell Cows.
Use a drop calculator if you're after a specific base imo. I was hunting high and low for a 4-socket elite bow for "Harmony" on my last two budgetazons - turned out my best bet was Hell cows (not an option for me as of yet) or NM Halls of Pain/Anguish/Vaught for the fastest, lowest-req'ts elite bow - Blade Bow. Finding stuff in NM also lets you go faster - less resists, more killing power. Don't forget to remove ALL mf gear, as it'll just prolong your searching.
Google "diablo 2 drop calculator" or use the one that comes with GoMule.