There are two parts to this. One is converting the data to NMEA 2000 so that it can be displayed on an MFD. The other part is displaying it. Assuming that your analogue senders are in working order, you can use a product like this
http://www.nolandeng.com/downloads/RS11_1pg_72010.pdf to convert the data to NMEA 2000. There are others on the market, but this is the least expensive at $240. The biggest issue with this is that you need to calibrate the analogue output to match you current gauges. This is easy to do when you have working gauges. If you don't have working gauges, then mechanical gauges can be used to map the sending unit output to the actual value.
Most modern MFD's will display NMEA 2000 data that is on the data bus. If you want a dedicated display, most marine electronic manufactures make a small display specifically for this type of data for around $500. Maretron has a display that allows you to configure alarm points on the data. It is more expensive at around $800.
I know someone how used the Noland Engineering RS11 to get engine data to display on a Garmin MFD in a tower and they are happy with it. It was installed by RJ Marine in Palm City, FL.