Exhaust gas temperature sensor location.

Hello. I am having a tubular exhaust manifold made for my Vauxhall Nova (Opel Corsa A) running a Z20LEH (2L 16v Turbo) from a Vauxhall Astra H VXR.

Am not sure were to locate the EGT sensor, do I fit one in the collector or one sensor near each cylinder?

If I go for 4 Sensors, what is the best way to monitor them? As I only have one gauge at the moment.

I'm using 1 egt sensor in cylinder #4( which is known to be the most lean in my engine) approximately 4-5 sm away from cylinder head. That's good enough for me but if you'll install individual sensors it will be even better for tuning as you will know exactly fuel trims in each cylinder. You can just switch sensors back and forth between cylinder after different pulls - it won't tell you the whole picture at once but it's definitely better than knowing just one cylinder egt...