Since you are going to get both eventually anyway.. I would get the carpet first and while it is growing to adult size be looking for, or building, an adult enclosure for it. Then once the carpet is ready to be moved over, replace it with a GTP in the enclosure pictured.
__________________
1.0 Python Regius 0.0.1 Morelia Spilota Mcdowelli 0.1 American Pitbull Terrier 55 Gal saltwater reef - cycling
~Derek
_sic semper evello mortem tyrannis_