They way we mentioned is same as u guys are asking, the diffrence is of knowledge,
I have mentioned that part but in a diffrent way,
its 5 valve/cylender,
4 cylender=20 valves,
Valves dose not depends open SOHC or DOHC, u can find 16 valves in both Sohc and DOHC,
The diffrence is in performance, efficiency, power gain, less loses, Etc,
2 are always batter then one, 
As far as the engine price is concered, Its a bit expensive,
Try to nigociate and bring it to 40k,
I can Give you a deal, 60K in which,
Wiring
Execels
Solid mounts
Front suspension
Engine with Low Milage (within 25000km)
Piping 2.5 inches,
15 to 20 days,
its a special offer,
TC,
Salman