While you are on the quest, Wrenix's Gizmotronic Apparatus will give you as many E.C.A.C.s as you request, but you can carry only one at a time; in effect, it will only give you one at a time. You only need one to do the quest, but if you need a replacement, it is readily available.
Just before you turn in the quest, you can get another E.C.A.C. to replace the one you used. Since Polly will no longer respawn for you once you complete the quest, the E.C.A.C. is nearly useless afterward (TBD if you can use it if you are assisting another rogue with the quest), and can be discarded.
Wrenix's Gizmotronic Apparatus formerly supplied (now poor quality). The Thieves' Tools are deprecated, no longer required for picking locks, and are no longer available from the sources that supplied them. Wrenix's Gizmotronic Apparatus still has an option you can select to give you Thieves' Tools, but if you click on it, you get an error message about not being able to carry more than one of these (when you have none).
Wrenix's Gizmotronic Apparatus can be found at 63.12 - 36.32