To make a very good ghillie suit, be prepared to spend many many hours though - I think mine took around 20 hours in total, including making the base. If suits like that linked had been for sale at that price when I made mine, i'd have been tempted to use one as a base to modify. In its basic form though, most of these suits fall down on a couple of areas: They have trousers - try walking any distance/go through undergrowth in trousers like that - you will tie yourself in knots/snag . The smock has the ghillie material on the front as well - this would be a nightmare when crawling. Material on the arms is a little too long for ease in handling items.
Id probably cut up the trousers, and stitch additional panels onto the back of the smock to add extra length to it (so it hangs just below the back of the knees, but keep it waist high at the front), trim the length of the cam on the arms, and remove most of the cam on the front of the jacket, possibly stitching in a panel of more robust material that wont snag/tear when you are dragging yourself forward on your stomach.
Something also to watch with these commercial suits - the cam is usually synthetic, and the cheaper ones won't be flame retardant, so take care!