Here’s my shop and home power configuration.

Power is fed from the grid into a 200 amp box in the shop.
The shop box feeds:
100 amp breaker (heavy gage feed wires out of breaker) feeding 240V to the houses 100 amp panel
30 amp 240V to the water pump
15 amp to a monitor heater to keep the water system from freezing (located in shop)
15 amp for lights in shop.

I need to install a transfer switch in the shop panel and send power to the house panel in addition to the water pump, heater and lights located in the shop. I’ll control the house draw by use of the breakers in the house panel.

What type of transfer switch is required and how would it be wired to split the load and distribution?

Thanks