Storage
So our self converted LWB + poptop is enough for 2 adults + 2 dogs for long trips in all weather. We do store stuff outside when we camp like dog stuff in a plastic crate and chairs + bbq etc.
With storage it’s not necessarily LWB vs SWB but how well thought out it is. You see LWB with less storage than SWB. Ours has taken a few iterations and refinements to get optimal with a place for everything with some thought about cupboards, shelves, and the like. This is where converters who do their own stuff that they refined over time, rather than flatpack are good.
Poptop
We got fitted later after using a couple of year without, which is something to consider if you cannot find the perfect van now. They are fine, don’t leak, some driving noise but hey, it’s a van full of camping stuff so not quiet. A high roof would also be fine. Both give more storage, and unless you are 5 foot tall, you need the headroom. We did without for a while, but without we needed an awning for anything more than a weekend
Awning
Used a drive away awning. The convenience of a van but with the drawbacks of a tent. So why not just get a tent. It just ends up being a place to put all your crap that you didn’t need to bring. Plus it blocks a window, camp somewhere with a lovely view? well now you can only see out of one side.