Do you have to order in a bundle or is it fine to get two deliveries?
I would say just build the computer using the stock fan then when there's enough reviews and such the get it.
If that's not the case (pun not intended) just get another case.
I would recommend getting the Corsair c70 as it has been tested to hold a h100i with push/pull and I worked out that the h100i is 27mm, and each fan is 25mm which is a total of around 77mm. Yet if you're not running push/pull it will be 37mm for h105 with an extra 25mm for the fan making it a total of 62mm (A full 15mm smaller than the previous setup).
Then if you're confident you have more space then you can put it into Push/Pull.
I currently have a case that doesn't support radiator cooling...