Sounds like you've already done some research and have the components so that saves you the hassle of getting quoted on a new system. Getting quotes is what gets me "a wee bit...." A case in point - I recently purchased 2 axpert inverters at a very good price, but it turned out the buddy who sold them to me didn't realize they were the 600watt MPPT version, so I put them up on gumtree, as I wanted the 1600watt version. Dude calls me to buy one after being quoted 62K to set up an off grid system in a .... caravan!
I went through the same bloody nightmare when I moved to the bundus with my partner last year, none of the folk I contacted for prices actually depended on the products they were selling to power their homes. Not one single one. And the prices quotes were off the charts. It felt like they nobody wanted to sell me components. They wanted to sell me components and installation. Eventually I ended up hacking together the system after doing the necessary research and self-education.
But back to the OP, if you find an electrician + and figure out your battery bank/panel requirements, those voltronic hybrid devices are not that difficulty to set up. They're definitely good value for money. I use the Axpert 3kva model that they build and I'm very happy with the quality of the device.