You can also go to Bartle&Gibson 13475-Fort rd 472-2850.They sell
M57 ballast for 62.70(175wt)
M58 74.25(250wt)
M59 75.00(400wt)
They also carry the mogule sockets.I did my own lighting with the m58 and I didn't burn anything down in the process
Keep in mind some of the magnetic ballasts come with a light coat of oil,which when heated up stinks like hell.It goes away in a couple of days.