I’m also not a specialist for solar power… But these are my findings and the stuff I bought so far:
There are two possibilities:
12V battery with higher capacity and then DC-DC convert to 24V
2*12V battery in series (=>24V) with lower capacities and DC-DC converter (for constant voltage)
My solar panel is second hand and has 170W but also a size of 1593 x 790 x 50mm. To big but was cheep. I’d suggest a monocrystaline panel due to its higher efficiency.
115W panels are usually sized 1015 x 668 x 30 mm.
175W panels are usually sized 1485 x 668 x 30 mm.
I’m not 100% certain about the minimal Umpp needed because you also have a 24V setup.
For the charger I suggest SmartSolar MPPT ones from Victron Energy. They are capable to work with 12 or 24V (autodetect) and have Bluetooth for statistics.
For the DC-DC converter I suggest the isolated Orion-Tr ones from Victron Energy. In my example I have the Orion-Tr 24/24-5 which brings 120W constant and 150W max). That should be sufficient but does not cover the constant 150W of the power supply which comes with the FarmBot v1.5. To be safe I also have the Orion-Tr 24/24-12 with 280W constant power as backup in the drawer it there are issues.
For the battery(es) I also suggest to go for Victron Energy. I have the AGM Super Cycle ones. For the calculations on capacity needed I’d suggest to have a look here: https://genesis.farm.bot/docs/power-farmbot-with-solar
If you have additional components you will have to take them into the calculation (i.e. rainwater pump). I’m completely overpowered (2 x 12V/125Ah => 3’000Wh => about 6 days at max power (500Wh) without charge ). There is no need to go this high. The batteries do have a high price tag (~600.- per piece in my configuration). So better calculate with less overhead and depending on what you really need. Maybe add a watt meter to your existing configuration and check what your consumption really is within a longer period of time (i.e. a month). This should give you real world data and make it easier to calculate the needed capacity.
I mounted the charge controller and DC-DC converter in a IP55 metal box from Rittal.
For Switzerland there is https://www.swiss-victron.ch/. They have all the Victron parts. Maybe also contact a local solar expert which could help you out. That’s what I did.
Don’t hesitate to ask if you have any more questions.