An easier solution is to do what we do. If you are near an ocean that has stomatopods, it is relatively easy to collect larvae the night that they are going to settle. Postlarvae are just as easy to rear as adults and you have avoided all the planktonic stuff.
When I go to Florida, Hawaii, or the South Pacific, I take a dive light (the brighter the better) and a 10 inch aquarium net. Four days to two weeks following the full moon, find some dark, open coast and wade out waist deep in the water. An hour to or two after sunset is usually best. Many species of stomatopod larvae become photopositive the night that they settle and they will swim to the light. Net them and place them individually into plastic cup d3/4 full of sea water. They will molt by morning and they can be easily transported in 2 oz plastic bottles placed in your luggage. (I have permits to import stomatopods, but you should check with customs and agriculture and definitely declare them.
Particularly good species to collect are Lysiosquillina, Squilla and Pseudosquilla. THey are large and easy to spot as larvae (2-3 cm). Check Google Image for pictures of stomatopod larvae. In the beam of a strong dive light, they take on a characteristic blue white glow that makes them easy to spot and while they are strong swimmers, it is fairly easy to net them. Also, it is amazing what else you will see swimming by.
You can do the same thing on SCUBA, but it is more difficult to collect the larvae. I place an inverteb zip-lock bag over the front of the dive light. The larvae will swim against the lens of the light, so all you have to do is quickly close the bag catching the larvae inside. If you have a large mesh bag in which to place the zip-locks, you can collect several bags full. The only caveat is that when you reach the surface, be careful when you try to pull the bags out of the water. The weight of the water will cause them to pop open, so hand them to someone one at a time.
Roy