pulling timeing?

I am getting ready to spray 150 what should i use to pull timeing? I have a window swtich and a msd 6a box. Should i get rid of the 6a and get a digital6?

I would get a Malllory Hy fire if I were you...it has a window switch, timing retard, rev limiter all in one! I got rid of my 6AL to get the mallory and I`m happy with it