where is the best spot to put the egt probe on the manifold and wheres the best spot for the wideband o2 above the stock one or belowit

 

It would be ideal to mount the egt and wideband probe somwhere central where it could receive a reading from all the cylinders, possibly where the last collector is on your manifold.

 

the wide band sensor should be mounted around 12 to 18" after the turbo outlet, reason for this, the control unit forthe wideband need to keep the sensor ata certain temperature, if you mount it too close the sensor can get too hot giving you false readings or error messages

for the EGT, if you're using an autometer if preferableto mount it 3" after the turbo outlet (like their instructions says)if mounted in the collector,depending on manifold type EGT can get higher then autometer scale, and if the probes break it wil lgo in the exhasut instead of the turbo impeller

 

Good call on that.