1) There is nothing special regarding those 308 casting heads - basically junk. Don't put any kind of money into iron heads aside from basic clean up anymore.

2) Port matching on something that mild will yield no noticeable results.

3) Standard Orange Box is fine. An MSD might make a noticeable difference in idle quality if your tune is off.

4) Why buy a roller motor then stuff a flat tappet into it? I would look into getting the factory roller cam reground. Could probably even reuse the lifters.

5) Headers are a must if you want to see 400HP out of that.

If the bottom end looks good, then put a set of heads, a cam, a better intake, center sump oil pan and a set of headers on it.

Enginequest heads or aluminum heads would be my vote. Find an RPM Performer intake used somewhere along with the oil pan and pickup tube.