i am the chef of a oklahoma sushi bar(should be an oxy moron) we get a frozen product that we commonly call sweet shrimp. they are A small sushi grade prawn that we serve as nigiri. we typically take the head off and dredge it corn starch and fry it. this seems to be similar to what you r writing about. most asian grocers should carry a shrimp or prawn of this quality. i would not use regular gulf shrimp and especially wouldnt use any funky indo asian mud shrimp.