how do invite some friends to a party with out hurting the other friends feelings.

You COULD try to be a bit devious by telling the friends that you want to stay over your situation and not let the others know about this sleeping over business at all. Or you could tell them all the situation you're in and hope that the ones that aren't sleeping over understand.

It is hard to tell to friends that you picked other people over them, but unfortunately you did not really have a choice. Maybe if you told your mom you do not want to hurt your other friends, she would let you have an other sleep over in some time and you could invite the other friends at that party? If not I would try to explain to them that you really wanted them to come to, but your mom did not let you invite any more people. You could do something else with the friends that can't come, like treating them to a movie or something like that, to make it clear that you really like them too.
If the party where all your friends are coming is at the same night of the sleep over, spend some more time during the party with the friends that can not stay. You will have plenty of time with the ones that are sleeping there.