hi, been welding a long time,have my l.a. city structural cert.looking at a used miller big 40 cat diesel,delux 15 kw. is this a good ,dependable,big enough unit?,or should i go a different route?getting a good deal on this one,it seems more guys i know like lincolns,vantage 500 etc.i dont think i have it in me to buy a lincoln.thanks mike