First, I would like to say that you may want to consult with your client. Dropdown lists that have 700-1000 items are very difficult to use. I would suggest a listbox instead, so that the user can see multiple items at once, and it will be easier to scroll.
I am assuming that you are not using data binding. (If you are I cannot offer advise, as I NEVER use them.) That being said, I would use:
CursorLocation = adUseClient
CursorType = adOpenStatic
You should also consider how often the data changes, and how often you want to reload the data. You may find that if the data doesn't change often cacheing the data will help performance.
Your client and you should determine what this means, and what the implications are.
John R Lick