yeah i'd wait on any new fish, i think what you might want to do is to put a carbon insert into your tank, that will take all of the meds out, and do a water change anyways (like you did

). then, if you still see ich spots on anybody, just raise the temperature (VERY slowly, maybe a degree per hour) up to 84 for two weeks, do thorough gravel vacs to get all of the spores up and keep an eye on everyone.
another thing, ich does show up on the body, but the majority of it is actually in the gills of your fish, so even if they only have a couple of spots on the body, they could potentially still be very infected.
also, do you have a quarantine tank? it's always a good idea to quarantine new fish before you put them into your tank, to avoid any diseases they may have caught from the store