The 2" hose is standard buy would think you could ask for 1.5" ............ but dont do that.
Go for the 2" and if you dont want to go for a 2" wand at this time then you can either
a) put 2" to 1.5" reducing cuff on the end of the 2" hose
or
b) as 2" hose can be a bit awkward to some people especially in tighter spaces ie bedroom, then you can have say 10' 1.5" hose. Still need the 2" to 1.5" reducer.
The 2" hose Solutions supply is quiet flexible and therefore you may feel no need for the 1.5" whip hose to the wand, but you may still find it advantageous for a upholstery/stair tool.
However, a 2" wand would be better then a 1.5", but is heavier.
I manage ok with my 1.5" wand. Still very good drying times.