I would go with the above, as long as you have oil temp and pressure you are good, if you must have water then it's the boost gauge that has to go
How are you splicing in the sender units?
Oil pressure can be Tee'd of the low pressure warning sensor, water temp usually involves cutting a rad hose and fitting an adapter tube
Wide band lamda is more tricky, I know the AEM had a narrow band output so you screwed it in where the OEM sensor went and spliced the OEM loom to it, I had a separate boss welded on the exhaust so ran both wide and narrow lambda sensors