I mean no offence to you REALLY! 
but that's what's wrong with this hobby and racing . Everyone want to pay someone else to do the work and then bolt it on? I realize lots of people can't weld . I'd say go buy/borrow a welder and in a weekend of practising you could weld up the k-frame yourself. The additions to a k-frame are not " structural" meaning if they fall off nothing bad is going to happen. Most skills on working on cars just need some confidence to just try! Once you figure out welding you will be surprised how often it comes in handy working on our pride and joys!
Besides you have to admit ANYONE including a monkey could lay down better welds that Ma Mopar did back in the day! 
I didn't powder coat mine, just a plain old rattle can after I wire wheeled it with a disc grander. We don't drive these everyday or in winter, the paint will hold up for many many years!
I'll hold my hand up as a "monkey" that did just what Brad suggested. I bought the stiffening plate kit from FirmFeel. I only had to do a little grinding on one of the pieces to get ithem to fit. The little bit of welding I've done before mostly involved evaporating rusty sheet metal on a project Camaro about 10 years ago. There was definitely some progress on the quality of welds (ok... they went from horrible at the start to not entirely terrible at the end), but overall the K member seemed to be a pretty forgiving item to learn on compared to a body panel. Originally, I was going to pay someone to install the US Cartool subframe connectors and torque boxes I bought, but I think I'm ready to try installing them on my own. In my case, this makes it a little easier to spend the $ on replacing the wiring harnesses instead of a aftermarket K member.
