I would avoid the C&L meters at all costs. They are cheaper to buy...but they are a lesser quality meter. Their calibration method uses a sampling tube instead of a wire element like the stocker and Pro-m/Pmass. The calibration is ofter inaccurate and unreliable...with much higher deviation.
In terms of gains on a stock car, i would say a 65mm TB might be worth your money, if you can get a good deal on one...but a MAF at this time just isnt worth the headaches. Wait till you do a top end kit then get a nice Pro-m/Pmass meter calibrated to 24# injectors and toss some 24's in there and be done with it.