I really need some advice here

Agree, build the 360. The 308 casting cyl. heads work well. Some port work, cleaning and maybe mill them some...A good goal would be 9.8 to 10.0 for street/iron heads. Not sure you need larger intake valves. If you only street drive this, you may see a more driveable combination with the 1.88" valves. As for a quick acceleration, have you ever considered a 904 with the low gear set? [2.74 vs 2.45] and the weight mass difference? I have run a 904 for many years with no problems. Good luck on your build.