I bought all my patch panels at Classic Parts and have not regretted it. All the panels were good quality and fit with little modification, other than the inner to outer cowl panels which were a challenge.
I bought an inexpensive MIG welder and did my own welding. Cheaper than a TIG by far or paying someone else.
A word to the wise...this requires little actual welding skill and more patience, measuring and planning than anything else.
Take your time, measure, cut, measure, fine tune, measure, fit, measure, tack, measure, weld (slowly, short stitches and let cool, don't over heat), grind, sand, fill, paint.
I did a lot of welding in my younger days but I still needed to practice on some similar sheet metal before attacking my truck as I had done mostly heavy structural welding with very good equipment in the past.
A decent small MIG welder can be had for less than $500 including gas set up. I bought a Lincoln at Home Depot. A small 4 inch grinder with metal cut off wheels is all you need for cutting out the old and fitting in the new.
Good luck!
Rich