greddy rs BOV
 

what would i want to hook the vacuum line to?

you can use the same thing as what the stock bypass valve used.

should i T it into the line?

you can if you want, T it off 1 line into the bypass valve and the other into bov. but the greddy bov will be quiter. and then the engine wont bog down in between shifts.

so would you recomend t'ing or just getting rid of the bypass ?(also where is this bypass valve?)

its all a matter if you want the car to bog inbetween shifts, or if you want the greddy bov to be louder, its your choice