Re: Which zapper???

 RE. It is recommended not to use TENS Pads because they have a high resistance when compared to metal electrodes such as copper. They are convenient but a poor choice for achieving the best conductivity.

I think there is an old school of thought behind such reasoning.
However, I'd add that significant improvements have been made with respect to TENS electrodes that I think are well worth mentioning. ie. 

1) TENS electrodes come in various types and sizes. 
2) Conductivity can be further improved with the use of a gels such as with ultrasonic conductive gels etc.
3) Electrodes can be cut or shaped to conform to specific needs. 

Most TENS electrode pads made today are made from silver /carbon based materials. ie. a thin coating of silver between the pad and the backing(where the actual wire connection is made). The silver not only results in an excellent conductivity between the lead and the electrode but also helps distribute the current electricity uniformly across the pad. While these pads cost slightly more than the traditional products they have proven to be substantially more effective than any homemade electrode that I've ever made and used since I began zapping on a daily basis. 

I'd also add that using these pads in conjunction with a good conductivity gel is the only system that has not resulted in burns and/or irritation after long term use. And more importantly, where these have proven to be reusable as well. However on the issue of conductivity here is what I found: 

When I was using my pure silver electrodes with cotton covers covered in electrode gel, I'd normally need to set my zapper at full strength on my wrist. However, when I tried the exact same settings using two pads cut to size, I had to turn the power down significantly on my machine in order to match the home-made  pulse strength. Similarly, the home-made silver/cotton electrodes would leave red marks and in some cases dark scare like patterns, on my wrists after a few days of continuous use, whereas the custom cut pads could stay on for an entire day without any side effects beyond an outline, which would leave shortly after they came off. And so as you can imagine, the TENS pads proved to be far better than the home-made electrodes for those who are zapping multiple times per day, every day. 

Having said all that. Here are some of the items that I've come to use in my term zapper treatments; electrode, pads and gel etc.

Long-life Self Adhesive Tens Machine Electrode Padso

Hope this helps. 

PS. Sorry about the size of the images, but I couldn't figure out how to resize them.