I have not had any craft store glitter that did not work with powder, even after curing..........yet. There may be some out there that will melt during cure time, but i have not found it yet.
Smaller size the better is my thought. You can tell how much flash a color will have pretty quickly through the packaging. If it throws off more colors that the one it actually is - i consider it holographic - and usually buy it to try it out. Pretty cheap for the most part.
For my painting style that i only dip base colors and tap coat glitters.......... to get it to show up best, mix it with plain clear powder and tap it on after you paint the main color. If you are trying to do a glitter along with the color in one coat, mix a LOT of clear in with just a little color. The more color you add in, it will end up covering up the actual glitter. Either way, i am not a big fan of dipping in the jar of fluid bed when it comes to glitter unless i am really racked for time.