New battery? alternator?

This morning i hit my remote start, and when i looked at my car, the headlights were flickering on and off, so i cut the engine and tried to start it regular. I just got a ticking sound. so i charged the battery for like 5 min then it started. So i thought it was ok, but then my gauges freaked out and all my lights started blinking. I think it is the alternator but i was just seeing what you guys think, thanks.
-Chris

Also i just got a system (xtant 600W amp, and an L7) but i didn't hook it up yet. If i need a new alternator should i get a larger (more watts or amps or whatever) one?
-Chris

i had almost the same thing happen to me a few months ago..i was having trouble getting it started then wehn i was driving , first the system stops working, then my gauges went wild and all the interior lights and driving lights went off, luckily i was right by a friends house so i went to his place and the car died...went to a garage the next morning and it was my alternator, so i changed it for an OEM one, YOu can get a 200 amp alternator if youre running a system, i didnt cause i have 2 batteries and a cap in my car.