Hi Larry,
Just leave the idiot lights and senders in place and install T-fittings for the new senders. If you are not feeding a hot water heater, you can use the ports for that by pulling one of the plugs and installing the sender. If you are using those ports, the T works well.
Our MD2030 also had all the wiring run in the stock harness with the unused wire ends simply tucked back in the loom on both ends of the run. All I had to do was pull them out and connect them to the senders/gauges.
I just got VDO (I think) stuff from NAPA. Two engines worth (oil/water) was <$100. The threads are metric on our engines.
Mark