That is a Vega oil pressure switch. It's the one I use. All you need is a
1\8 inch pipe Tee and a starter switch ( to override pressure switch while starting) I think I spent less than 10 bucks.
As long as you have this safety switch it's as safe as mechincal injection. (hilborn style still has high pressure from pump to barrel valve)
Bobby Layne
2011 MLS Champion