How to invite people to Bachelor/Bachelorette without a wedding party

My fiancé and I are opting to not have a wedding party (cut costs a little plus we have friends on both coasts and to include everybody the wedding party would be HUGE).

We are still going to do bachelor/bachelorette parties and invite everybody we would have included in the wedding party. For me, that's going to be a total of about a dozen girls (including myself).

Even though they're not going to be my bridesmaids, I want them to feel special (because they are!!). So I'd like to still get them little gifts/an explanation of our plans to still include them. Think "I can't say 'I do' without you," but make it very clear that it's not a bridal party.

Looking for ideas on small gifts that would usually be included in "Will you be my bridesmaid/groomsman?" boxes, and a way to explain in a heartfelt but clear way that I want them to come celebrate together.