Starting, Electrical Problems on 91' GPSE

I have a 91' Grand Prix Special Edition. I have been having major electrical problems and starting issues in the past few weeks. I had to replace my alternator at the beginning of this Jul, as my old one was squealing and sparking and it was smoking rather annoyinling. Anyhow, since I put the new one in, I have been having alot of problems starting my car. I have had problems with previous starters in differnt vechiles, and all of them the starter always grinded on me, or made some kind of sign that it was dieing, then it would just die. This one, I turn the key and it clicks, sometimes it starts, sometimes it doesnt. Took my a half hour to get it started earlier today, but sometimes I don't have any problems. So I am not sure it is the starter. Plus My new alternator isnt charging all the way. My volt-o-meter as I think its called is showing about 2 nothces less that what it should. I think the middle is 16 or 13 i dont remember. Anyway its not putting out like it should, but sometimes it does. It fluctuates when I hit the brake, turn vents on, headlites, radio etc. But when I do alot of those things it goes up, not down. I was driving the other day and while I was driving all of my gages was going nuts on me. My radio and everything kept flashing, I had to reset my clock like 5 times. All of my dash gages were sputtering up and down. I could hear my engine adjust to the flux of rpms. And it stalled about 14 times. Well, didnt stall, just stop running. Most cars when the stall the engine baughs out or sputters or something, my car just shuts off. Any Ideas?