I will admit up front that I have no clue what tzv, tez, tttv mean... and that is at age 75 with 55 years in the business and consulting nationally for the last 20... if you could spell that out for me I would appreciate it. Perhaps you mean TXV, EXV, thermostatic and electronic expansion valves. If you can clear that up I will appreciate it.
Regarding the situation where you only need the cooling option, it will be vastly cheaper, and a whole lot more reliable to buy a ground source cooling system only...not all the complexity that comes with a heat pump...nor the 2 stage or variable speed blower feature.
So far it sounds like you are a retailer, and not so much a technician... my words for you are that very high quality local service company is an absolute requirement for buyers of these or any ground source heat pump system.... if you want to increase sales, work with a local ground source heat pump specialist, well established and with a good reputation to supervise the installation and provide reliable service.
the more frills and features, such as two speed or variable speed blowers, (all quite wonderful) are virtually impossible for anyone but a well established heat pump specialist to service and maintain... those are a bit like rocket science inside.
On this end I see home owners living 60 or 100 miles from the nearest town with even semi qualified technicians buy ground source heat pumps or other complex equipment, these loose badly on such a deal.
So far I have not been able to locate a ground source cooling only system for you. If you buy in volume however some manufacturers would happily produce cooling only ground source systems. I will spend some time searching that for you.