I'm just an engineer, but I probably spend more of my money on cars than I should. And while it is not like going to walmart and picking up a box of shells a blower is a very cost concious approach for this guy. He has a solid short block and wants good street power. he could go out and buy new heads, rebuild the bottom end, get a enw valve train and end up with a 11:1 semi-race street engine, or for half the price he can make the same power only more reliabley and with more torque... A mini-blower is perfect for this situation.
As for the carb question- yes you can reuse your old carb but you will need to retune it, I recomend reading up on it, asking questions, and trying to do it yourself. It takes more time the first go around, but if you want to claim being a hotrodder I believe you should have dirt under your finger nails.