Help with stimulation electrodes

Hello everybody, i am trying to setup an electrophysiology recording unit in my lab, to be able to record field potentials from rodent hippocampal slices. However, i am facing a lot of difficulty in selecting the appropriate stimulation electrode for my purpose in terms of its impedance, tip diameter, shaft length, metal, and other related details. i am highly confused and have tried to look at existing papers where in such work has been done, but it has not been of any great help.
Please help me out with this.