The glycol/water circuit (generally 50/50 mix like would be in an automobile) is not uncommon. Glycol/water is used as a medium to transfer heat from the process to a refrigeration system. You will have to determine the flowrate and temperature of glycol/water you require when you size your heat exchanger. This circuit is not part of the 'package' from the vendor. The refrigerant package consists of compressor and freon circuit which is used to chill the circulating glycol/water mix. These refrigerant packages are offered in 'standard sizes' pre-engineered by vendors who supply them mounted on a skid. Once you determine the flow, duty and temperature of glycol/water you need, then you choose the refrigerant package that best fits while still having extra capacity. There is usually some equipment design iteration required since the closed glycol/water circuit should match the refrigerant capabilities. The details are somewhat tricky since it can be difficult to assess how the vendor refrigerant package will perform under various process loads.
Because you are purchasing a refrigerant compressor, this system is not a cheap option compared to using cooling tower water for condensing at a warmer temperature.