Inverters are the coming wave of technology, they use less enegry and produce the same outputs as other machines. The question for you is this what are you welding? Mig and tig require different machinery, mig will require a CV machine and tig uses a CC machine. CV is constant voltage output and CC is constant current. I believe you will want to look at the miller website{ www.millerwelds.com }. If a 130 amps is all your looking at then .125 thickness is going to be the tops for full penetration. I would look at millers millermatic 135 { non-inverter} or passport{ inverter} both are mig process. In the tig process the maxstar 150sth will be the entry model.

Hope this helps,