Do I need another Spark?

Can I connect the 14 valves, (two extension boards), 7 temp sensors,2 pumps, HLT, BT, fermentation fridge and heater on just one Spark? I cannot figure out what is the right way.

Yes, you can. With the following caveat:

In my own experience, having all many devices on a single OneWire bus could cause issues. It is sensitive to wiring quality and length, because of the load on the bus.

This is why I made plans to create a new valve control board with 8 outputs, instead of the current one with only 2 outputs. I will also let it communicate over RS-485 instead of OneWire, which is also supported by the Spark. This protocol is better longer networks.

So you don’t need another Spark, but you do need a different valve control extension board.
I’m going to try to outsource the board design to a friend, because I have too much work on my plate and the board keeps getting delayed.