if the engine is running right you should see 210bhp and around 230lbft of torque. The filter will give a small increase but its mainly there just to help everything flow better. The diverter valve is needed to cope with the extra boost from the remap.. the standard valves have a rubber diaphragm which splits/leaks.
Have a browse through the mk4 section you should find some help with best places to buy stuff etc.
