I went electric because my brewery shares my garage with my antique motorcycles, and gasoline and flames mix way too well.
The Electric Brewery
has a great setup. I used all his kettles and plumbing and pumps and RTDs and everything works great. Zero complaints after 25 batches.
My control panel has the same functionality as his, and actually shares a lot of the parts with his - the big power relays and SSRs, are essentially the same (except I sourced them from Eaton/Cutler Hammer instead of from an eBay seller). My enclosure, heat sink, and much of the power wiring and connectors are mostly the same or similar.
Instead of his switches and knobs, I went with a software process control approach. Insane - it took me a year's time, and a thousand hours of programming. (I retired after 30 years in computers and electronics). It too works great - zero complaints after 25 batches.
One big plus (for me) is that during the hot summer or cold winter months, I don't have to spend the day in the garage - I can remotely monitor my process from a browser in any nice warm (or cool) room in my house.
Take a look at Broad Run Brewing
. You might find a couple of good ideas there.
P.S. Electricity is cheaper than propane, and it will never run out halfway through a batch.