There really isn't any welding required on most suspension lifts, most are bolt-ons. Only one of my previous suspension lifts required welding but that particular lift, a Rubicon Express 4.5" long-arm suspension wasn't worth the effort to install... it just didn't perform well in the offroad conditions I ran it in.
The vast majority of suspension lifts can easily be installed with standard hand tools at home, you just need things like 6-ton jack stands (3-ton version aren't tall enough) and some kind of a hydraulic floor jack. And those little floor jacks in the blown-plastic cases like you see on the store shelves are more frustrating than useful. Harbor Freight Tools has inexpensive floor jacks that are big enough to do the job. I use a 3 ton HFT floor jack on a regular basis.
Tool-wise, you will need both metric and SAE sizes.
I'd add Currie to the list of suspension lifts to consider... they make one of the most widely respected suspension lifts and it too is a bolt-in. My current 4" Currie outperforms my previous 4.5" Rubicon Express, 5" Rock Krawler, and 3" Tera suspension lifts in all regards by a considerable margin.