B20 would definately give you a bigger push than B18C. Price depends on how much of the work you plan to do yourself. If you're paying someone to build you a B20, it may come at a high price depending on who you go to, how well you know them, and how well they even know how to build one. Keep in mind, buying a complete motor ensures you that at least you're not getting shortcutted anywhere. the motor is complete as-is and was factory built. having someone else build a B20VTEC for you could be complicated.