Bellezza28, yes the Ocean Club will accept these Marriott Checks as will any marriott property world wide. They are sent in $50 amounts so you would get 20 checks per $1,000 reward. If you are an elite member, it takes 135,00 points per $1,000. Non-elite is 180,00 points. I redemed two awards for $2,000, upon my arrival, deposited them in my room account so I didn't have to take the time when checking out to sign each and every check.
To get these you can do it online in the Marriott Rewards section and I think it is under the gifts redemption.
Your kids will love the pool area as it has slides, pirate ship and is multi level. The rooms in the Ocean Club are two hotel rooms combined to make a 2 room/1 bedroom unit. Has two bathrooms, microwave, refidge, dishwasher. You also may want to look into staying in the new Lahina tower that just opened in June.
You'll be much happier at the Ocean Club than the Marriott Wialea especially if you have young kids. The Marriott Wialea recently finished an upgrade. The rooms are outstanding, the main pool is no bigger than a thumbnail, but I think they where planning on expanding the pool.