VBA Form Guidance

Hi,
I'm looking for a little help in thought process - how best to make this form work.

Form is opened when workbook opens (command button on sheet will also open form)

Select Item1 or Item2

Item1 - SQL query runs and gets all names to load comboNames
choose option: namesA or namesB --loads combo box with selected type of names
choose name from comboNames
click the button and it runs an sql qry to get the data for that name

Item2 also gets names, but they are different names.

All the names are loaded to the same 2 locations (namesA and namesB sheets)

The question: if they reload the form after the first choice, the Item1 and Item2 buttons are cleared, the names for Item1 (or Item2) are still loaded, but I'm actually going to get them again when they click on Item1 or Item2 again.

When or how should I load/unload or check for existing names?

Thanks!