Hello,
Yes the conveyance deed as stated by you will happen to be a valid deed as it satisfies all the conditions of a valid conveyance deed which is also followed by a confirmation deed.
A conveyance deed is essentially one wherein the seller transfers all rights to legally own, keep and enjoy a particular asset, immovable or movable. In this case the assets under consideration are immovable, namely property. On signing a conveyance deed, the original owner transfers all legal rights over the property in question to the buyer, against a valid consideration (usually monetary).
You may please share with us the content of deed of confirmation, so that me may give you a concrete opinion on the validity of the conveyance deed after the execution of deed of deed of declaration.
Regards