What I want to do, is allow the user to select ALL results, or only the results that are above the specified limit for each limit
A simplified version of your query/stored procedure might look like this:
SELECT [Field List]
FROM MyTable
WHERE SomeColumn>@SomeValue
so you would only need to pick one value. So you should be able to just use another dataset to get the values for the picklist. If you think about it, what's the difference between
x>5
and
x>5 and x>4?