if you have a 1200w xplod amp what size speakers and sub should i have?

You need to check how much power your speakers can handle. 1200 watts can drive 6 inch speakers as long as they can take that much power (i.e. bigger magnet on back).

With 1200 watts I'd guess a couple of mid-range speakers of your choice and maybe a ten inch woofer or two, or just run the subs through the amp and leave the speakers to the radio.

Although size matters (nyuk nyuk) some here, it's not completely necessary. Subs made by sony with the same label (xplod) should be ok, but double check with a salesperson on the power rating of those speakers (how many watts it can handle).

Have fun! My crap town recently passed an ordinance that prevents loud music.