Spot Welder?
Lenco L4000 is what we have . We have an older blue one and a newer red one. These are about the best that I have seen for the money. We bought the last one used for $125. You always see them at auctions and usually sell cheap. They usually sold for over $1200 - $1500 new but they sell for much less used with missing or worn tips. The tips set is only $30. These welders are small but very heavy and on wheels.
There are places where you can use a portable pinch spot welder. This style is what I use anywhere possible. The lenco is used where the pinch style won't reach. But you can use the lenco everywhere.