I wouldn't go for a modified motor until your tuning is down good. If you can tune a motor that is out of wack, and bring it back into tune then you would be ready for a modified motor. Tuning is the key, learning to drive is easier and less costly. If you can't tune a motor, you would be really wasting a good motor, especially if you paid extra to get it modified. Be honest is your evaluation of your skills, it could save you lots of money if you are honest about it. Having all the top end speed or long run times means squat if you are killing the motor in the process.