Didn't use a welder to make my brackets. Drilled eight holes and cut a two clearance notches. They're every bit as safe as stock seats and probably safer than Momo brackets. I used the stock sliders.
I can't take the credit though. After designing a good functional part I found this:
http://members.dodo.com.au/~wawawa/seats.htmThey looked every bit as functional and were easier to make than mine so I went with it and they work perfect.
For my wheel I picked up a Momo hub from one of my suppliers. They're primarily a VW supplier but they'd had an E30 adapter sitting on the shelf for a few years. Got it cheap ($45 shipped). Grabbed one of my spare Momo wheels, dated right around when the car was made, and a Benetton F1 horn button. Only down side is that most steering wheels would do better with a 1" spacer behind them so I'm going to have to pick one of those up.