Try dif searches, (try just spot welding cells) and sort thru the crap, if they have been around for more than a few months it's almost certain to have a few reviews.
In our older thread we talked about this b4 you rightly moved it
And I made some comments about the design and danger of fully charged caps. You can sort of ( only sort of) ignore those comments about the danger in capacitors, where this design is concerned, but understand they can hold lethal charge. When I quickly looked at this it looked like another one I had seen before a long time ago. With that one you hold like a tattoo gun, brilliant one hand operation, both electrodes fixed the the body of the machine, AND I MISTOOK IT FOR A DERIVATIVE OF THAT, (but I only looked quickly). In that design (which this isn't) a potentially sweaty palm would be wrapped around two BIG uncased caps, which is really could be potentially lethal, BUT THIS IS DIFFERENT, you don't hold onto it, you use leads like mine, so far less of an issue, but be aware of the charge the fully charged caps hold and don't risk shorting them, you may not get a fire like with the battery cells, but you will get a fierce explosion, I accidentally did it with a much smaller cap than in that welder, it was a blinding flash and the debris from the cap covered the entire room. As safety glasses are only a couple of $ I would wear them (I do when using mine).
Keith
PS The only other comment is you might want to extend the leads, like most of these fairly low cost welders they are a bit short, if you do make sure to use a similar (or better as you are extending them) current cable, (I used the cables from an old car jump start pack that was dead in my garage, pure copper, very high current carrying) If you put a joint in the cable, solder it then shrink wrap it with a couple of layers of SW, or if you have any self amalgamating tape, (not sticky tape, wrap the rubber tape tight round the joint then roll the joint in your fingers and the rubber amalgamates with itself forming a solid rubber coating, its cheap to buy now (used to cost a fortune) and has been used to make waterproofs joint underwater, so its good stuff. Or alternatively buy some suitable cable and the correct connectors then replace the entire leads.
But if you buy it you can obviously try it with the leads that come with it first, just be aware its east to extend them if they are uncomfortably short. If you extend them you will probably need to slightly increase the weld power, that will be adjustable on the device. No big deal.
batteryhookup.com
There are other ones cheaper and some have more options.
" But once you realise someone knows what they are talking about, (and if you can hear and understand the sound track ..... LOL... 
