Rad box airflow

Im building an external rad box that will sit under my lian-li case.

Is putting the rad at the bottom of the box with the fans sucking air through it and out goin to hurt airflow?

There will be an 1.5 inches of clearance on the bottom and 1 inch of clearance between the bottom of the case and top of the box.

Should i just make it like everyone elses, radiator on side fan on the other?

IMO there is only one proper way to make a radbox. First, you must make the box as airtight as possible. Mount the rads to the side of the box with a cutout in the box for the rad (obviously) and make sure to seal the rad to the box with some corktape or weather stripping or something. Now decide where you want your fans; The placement of the fans is of little importance, all fans will EXHAUST out of the radbox. Doing so will bring fresh cool air in over the rad(s) and only over the rads as the box is airtight except for the rad hole(s) and fan holes.