they supply a Zyxel VMG3625-T20A , if you don't know what you doing best to just go for theirs (just know that they manage everything) - but I'm guessing you know so what you doing so don't go for it

I took their second option where they subsidise like 800 bucks and you take what ever router you want and you pay the difference (if they can source it) and you manage it how you see fit (there a clawback on taking their router or the subsidy 6 month i think)
if you happy with your ASUS you might as well keep it and skip the clawback period , but Im happy with them so don't think you will want to change.