Welcome to this great forum.
150bhp is plenty, unless perhaps if you’re towing, with slightly better fuel economy and lower emissions. Accelerates really well and will cruise at 100mph all day if you need. But drive them both if you can, and see if you need to blast off the line and send the contents to the back of your cupboards!
Best option box I ticked might be the towbar. Taking bikes with us (and getting into the tailgate easily) means we can leave the van set up and explore locally easily, and drink and ride!
If you’re getting an Ocean though, I don’t think there are many essentials that you’d miss if you didn’t tick them.
Colour is the main conundrum. I’m very happy with the free Ascot Grey. It looks sandy in some lights and true grey in others, blending with its surroundings quite well. Darker colours are harder to keep clean (if you’re bothered). White is good if you like 2-tone, you can wrap the bottom half any colour you like, protect the paint and save yourself maybe £1500 over factory paint.
I wouldn’t hesitate too long ordering though, as the 6.1’s days are numbered (I don’t think anyone actually knows that number, but sounds like it’s weeks/months rather than years).
Finally - use Drive the Deal or similar to save c.10%, and look forward to smiling whenever you see it never mind use it.