last year i ordered 100 lbs of oysters for daughter's 30th bday from the link that is below. they were the hit of the party. would definitely order from them again. the gentleman's name was "broox" (i think) and he was great in communicating and timeliness.
You can try Louisiana Foods in Houston. A problem I might see is shipping. Any thing I have had shipped in to Houston arrives with melted freezer packs, although it was for my mother's funeral in August a few years back. Once May comes around, temperatures will be in the mid- eighties to nineties.