I had a Steca controller in my old caravan and it was easy to use and always worked, so I stuck with that brand.
We bought 2 x88amp hour calcium plated leisure batteries (about £100 from ebay, yes I do love ebay!). We thought that 2 batteries would be better than 1 big one (122ah) for about the same price. If anything goes wrong we will have a spare, and this way we have more capacity and will hopefully keep them above half way discharged (the charge controller should help with that a bit).
I have also bought a 100amp heavy duty relay and a smartcom self switching relay (ebay about £10 each). This is (the cheapest way) to charge the batteries while the engine is running. This is how other people on the sbmcc forum have done it, so I am copying them! More details on this when I understand how it works.
We build a box for the socket to live in so the wires don't keep falling off. The socket charges the laptop and the phones. There is also a fire extinguisher, just in case!
Here is a light. Working!
I still haven't connected the smartcom to charge the batteries when the van is running. It is sunny at the moment so the solar panel is working fine. We might even sell the second panel (be bought 2x 40w , but only mounted one on the roof).
As we are not running a fridge we don't need that much power and one panel (and a hook up to charge while driving) will probably be enough.