I would like to know if timelock transactions are considered standard with the current bitcoin client. If the answer is no, this means that you should use a different client or is it up to user choice? Furthermore, if someone wants to construct such a transaction which is the structure it should have?
nLocktime has always been standard and is used to prevent fee sniping.
OP_CHECKLOCKTIMEVERIFY is currently not implemented and is not enforced.
A non-standard transaction can be mined by a miner, but will not relay around the normal peer to peer network. A transaction who has a
nLockTime which has not been passed is invalid, and won't be relayed or included in a block until this time has passed.