One of the best vegetables for shrimp and prawn wok recipes is the green snap pea (also known as sugar snap peas). With snap peas you eat the shells and all and preparation for wok cooking is minimal. At most you'll want to remove the tough strings if they are present, otherwise no preparation is necessary.
Look for green snap peas to use in your jumbo shrimp and prawn focused wok recipes which are plump and crisp. A few blemishes on the outsides won't hurt, but if you see depressions or soft spots avoid them - particularly if you will be storing the snap peas for a while before cooking them in the wok recipe you are making.