What size exhaust should I put on my tc ford cortina it has a fully worked 2ltr pinto engine and extractors and what mufflers or how many mufflers I want it to sound nice

"Fully worked" is a fairly vague description, but from my reaserch and own experience -
 
for an engine set up purely for motorsport, around 190 BHP plus you could go to 2.5 inch
strong road / occasional motorsport engine 150 - 180 BHP 2.25 inch
warm road engine - 2 inch
As for mufflers, a good sports muffler and a resonator are usually a safe bet.