Loki,
Definitely go with a dual out header, not a single with a Y pipe. It will sound better. Also, Flowmaster 40 series cost around $80 a piece last I checked, but i got mine used for $75 for the both. Just look around. As for the series, go with 50 series, they are loud, but if you get sick of them, you can roll the windows up and you really cant hear them at all. I love em!!!!!!! As far as intake, just upgrade the carb to a 2 barrel, either a holley 5200 or even better, a 2300. Ask around a little and look at previous posts on here and you will find all you need as far as that goes.
Matt