If you do not have the time and skill to do it yourself, I suspect you will put way more money into a bus conversion.  I suspect resale value would be lower, so you'd eat it on both ends.  I also suspect the same materials will be used for your conversion as for rv's.  I rather doubt reliability will be any better than an rv.  
And repairs on the conversion ( if you cannot do them yourself) are likely as hard or harder to have done in a timely fashion ( fewer choices of repair people, I would think).  If you think a bus conversion with business graphics is stealth enough, then would a class a or c with business graphics also be stealth enough?
I'd have different thought if somebody wants to do a conversion themselves as a labor of love.