Depending on the build the 347/331 isn't all that far apart in power. Most would prefer the most cubic inches possible but that is not always the case in different builds. I have several 331's and 347's and for the street I prefer the 331's but only by a slight margin simply because of the torque curve I have gotten from the ones that we have built. Either combination would be fine. If you want to save money then you can build a mild 306 with some good heads and a blower and make enough power to get deep in the 10's. I have several 306 engines running 10.0's and could easily be in the 9 second range with a little effort.
I have seen a bone stock 302 with an old "A" Trim on it running 12.20's. The only after market part on the entire car was a 3.73 gear and a MSD 6AL box.
I thought you were doing a budget build but if you have 20k to sink in an engine in the next 12 months you need to Call Steve Petty @
http://www.prolineraceengines.com/ and let him build you one and stop worrying about all this. You can tell them that I sent ya! They do awesome work and leave all the guessing and stress for you out of it.
That BBK intake is a P.O.S. IMO. like JRD said. No where near worth the money even though it does look kinda cool.