You've not said where you're located - - -
We looked at Jerba - only 2 hours from Stirling - and were impressed. We were also pointed to Exploria in Brighouse, who are 4 hours away. We ended up going with Exploria for no other reason than the person who recommended them had done so. On reflection, while we'd probably have been happy with either (and we have friends who are pleased with their Jerba vans), I have to say I like the quality of the detail finishing on the Exploria conversion. For example, if I were to show you round our van, I challenge you to find the water pump, the leisure batteries or the gas cylinder. We have had occasion to have to have remedial work done this year, and the 4 hour journey time essentially meant we ended up making a 3 day mini-break of it as they needed the van for a full day. We stayed locally on the first night, and then played tourist on our way home, again with a night away. But distance is something to consider!
I'd never heard of Autohaus until recently, but all our friends with vans are either Jerba or Exploria conversions. This may be a self-fulfilling echo chamber, of course!
We liked the idea of the Wallas until we found out how long it takes to heat up for cooking, and of course it will be considerably less responsive to heat control for normal cooking. We also didn't like the fact that it outputs the heat at waist level. We choose an underslung diesel heater, fed from the van's tank, which outputs at floor level. We have 60 ltrs of underslung water. We didn't consider any toilet options at the time (4 years ago), but have subsequently got a small Thetford and a Khyam toilet tent - no way will we be toileting in the van! Fridge is electric. Hob and oven/grill are gas (C/gaz - 907 - I carry a spare 904)). We've used the oven/grill once in 4 years - - -
Some other thoughts you may want to factor in. These are things we didn't know we needed to know when we were researching, and we now regard as "thank goodness" we ended up where we are! As regards the pop-top roof, ask about load rating if you plan on having a roof rack for a box, kayaks etc. Check your chosen seat/bed is easy to transition from seat to bed. Check you can get your feet on the floor in seat mode, and you have enough headroom when the roof is down. Is it crash tested or pull tested? Does it rattle when you're driving? We opted for a VW Cali seat/bed which is expensive, but safe - it's on rails, so we have a lot of flexibility with how the load space can be utilised. When we have passengers on it, it's usually pulled fully forward which is much nicer than being stuck at the back of a van on a long journey.
I appreciate you have decided on SWB but unless you are completely wedded to that, consider the practical benefits of the extra space in the LWB. For us, with the bed down, we think we'd struggle to sort ourselves out for bed if we'd chosen SWB. A reversing camera helps enormously.
I assume you'll want swivel front seats - the VW ones raise the driver's seat height a lot apparently, and you lose adjustability. Others are known to rattle, and rock a bit. I can only say that Exploria have their own ones, and I have maintained adjustability, and original seat height, and they are solid.
VW OE sliding windows leak. If they don't leak now, they will. They will always leak. We had ours replaced with fixed glass as we'd ordered a Kombi with sliding windows. Don't get VW sliding windows.
We don't have solar, although we did get the necessary wiring put in to make retro-fitting easier. Thus far, we've never run low on power but then we do have 2 big leisure batteries, and all the interior lights are LED. I see you've wisely chosen LED for the vehicle lights - and the soft-close door(s) are worth having.
