Being a retic of any size potential his appetite is going to be big. Did you get any other info on the parents? Curious if it's the same snakes that produced my 50% SD Ultra Ivory het Anery. I haven't seen Bob list any platinum/fire SD that weren't at least het Anery as well. I know the parents of mine were 6' Ultra Anery dad, and 11' Platinum/Fire het Anery mom. Both 50% SD I believe.
Mine was a year old when I got him and Bob still had him on rat pups every 7-10 days. I increased prey size to smalls, then medium, and soon to be on large rats all within 8 months. He keeps his small hatchling stock on maintenance feeding schedules from what I can gather in order to keep overhead costs down as well as for the fact that it's easier to sell and ship a small snake than a large one. After I got my boy eating a bit more heavily he's tripled his weight (500grams to 1500grams) and grown over 2' since I got him. I'd suggest hook training/tap training if this is your first time working with retics. Their feeding response is incredible to say the least. Definitely a "bite first, ask questions later" type of response. Purpose is to very gently tap them with a hook alert them to the fact that they aren't being fed whenever you need to handle them or get in their cage in order to turn off their feeding response.
The cage being built should be plenty big to house him comfortably for the rest of his life as well.
Week of settle in time applies to any new animal in your care when first acquired. Is this your first retic/larger constrictor?