AJ Botha

I am municipal fed and have a three phase borehole pump. 

I would go for three Growatt SPF5000TL at around R10k each, then one Pylontech US3000C for around R17k, the rest of the money will go to solar panels, cables and other accessories. As for the installation, you will have to DYI. 

You make no mention of exploring going completely off grid in the future - which I suppose might change the conversation somewhat.
If I had 150k to implement something to meet your listed requirements. I'd probably go with :
 
A 15kw grid tie option in the form of a Solis
https://www.diygeek.co.za/product/solis-4g-3-phase-dual-mppt-dc/?utm_source=Google Shopping&utm_campaign=Google Shopping&utm_medium=cpc&utm_term=7589&cmp_id=9588290156&adg_id=95763655101&kwd=&device=c
 
25x 590w PV Panels
https://jcsolarpanels.co.za/shop/solar-panels/canadian-solar-panels/595-watt-monocrystalline-solar-panel/
 
Plus Backup:
That Pylontech you mentioned.
Basic inverter like that Growatt or whatever spec'd for your critical loads.
Perhaps something future-proof along these lines
https://www.sustainable-energy-solutions.co.za/products/rct-axpert-max-8k48-8kva-8kw-48v-hybrid-inverter?variant=39989541732510&currency=ZAR&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic
 
Didn't fully run the numbers but I think there'd be bucks to spare for cabling, rails, isolators, breakers etc.etc.etc. And yes, DIY installation - it's fun
 
Just my thoughts and might not be a popular method
makes me wish I had 150k for my own project

Just be aware that what you're doing is illegal according to the Eskom SSEG guidelines. You'll have to register and get a new meter.

On this forum, people often substitute "hybrid" with "bi-directional" and confuses everyone. Of course, the Growatt is a hybrid inverter! However, it's not a bi-directional as some other brands, therefore it cannot push to the grid side to supplement the non-essential loads or feed to the grid.