If I go with adding windows to a panel van then sound deaden/insulate and carpet, how much of that is then a waste or problematic with pushing forward with pop-up roof and full units in a years time? Is there a way I can just do the basics and minimize the waste for future options? Do the roof as a seperate removable panel type of thing. Speaking to a couple of conversion companies they prefer it to be a shell if they are fitting kitchen and roof. Just find myself rushing in this way but also don't want to spend a couple of thousand taking it away from a bare panel van and largely wasting that cash.