O2 Sensors etc 1999 Disco II, 150k miles

All:
 
Looking for help with part numbers for the $70 O2 sensors. I'm looking on websites and finding good descriptions for the 170$ ones but vague and not so helpful descriptions on the 70$ sensors. Even with the same brands. I think I would like to go with Bosch...from what I'm reading. Anyone know the part numbers?
 
Also, I want to do catch up maintenance with wires/plugs. Will get magnecor and bosch +4. Is there an issue with changing the O2 sensors BEFORE the plugs and wires arrive?
 
Thanks!
 

Before or after won't make a difference, buy your 02's at Atlantic British that way you will get the ones needed.
Once you get your wires and plus, get back to us so we can help you install them without removing the manifold.

Thank you, just want to verify...the pre and post catalytic converter O2 sensors are the same?
 
Good to know I can change them without taking the truck apart:)