Hi Michael, thanks for your response.
I just mean two different levels of stickies. Another way to think about it is that each of my posts represents an advertisement, and there are gold, silver and bronze levels of advertisements. Gold advertisements are shown above silver and bronze, and silver is shown above bronze. If it was just a two tier system then I could use stickies for gold advertisements and non-sticky posts for silver.
I did have a look at those plugins earlier before posting. The second only allows for a two tier system. The first I had high hopes for but there is no way to set the sticky level of a post when it is being created (or by later editing), you have to individually set the different levels within each category and tag, which will be cumbersome with a large number of posts, tags and categories.