a deal......my, what do you mean.....
A good deal would be a head in exchange for money......lol...sorry.
Well, prices vary depending on the spec you want. usually about 350 for a mild 16V head, up to 750 for a full race item.
And power gains vary so much. When working with modified heads, its most important not to expect them to give an outright power gain. It doent work like that. Slap a race head onto a std engine and itll run like poo at low rpm.
When you use a modified head, its dictates the power POTENTIAL of your engine. A modified one will allow more power than the std item. But if you run the std cams and TB then gains will be minimal. But jump to quad TB;s and wild cams and the worls is you oyster.......and think along the lines of 200+bhp.
a mild head is all youll need for even a well modified engine.
Larger inlets and exteneive flow gains wont be that beneficial until your pushing the envelope, and thats expensive. But decent components really help. Since you deal with Kent cams, i would think you would be able to experiment cheaply with different profiles........but remember....170bhp sounds alot more than 169.