the Kenne Bell is the top choice for twin screw.
Whipple is similar but not as efficient.
Both of these blowers make torque way down low where you'll feel it, they are ideal for street cars.
Vortech is a Centrifugal blower so it makes progressively more power as rpm increases. It won't have the torque down low like the first two.
Figure out what your budget is and driving style will be and go from there.
I laugh when people say 'I'll be happy with 700 hp'. The truth is you can never have enough and will want more.
