How to access items in a category from SuiteScript?

We would like to access the list of items for given category using SuiteScript while maintaining the order that the items appear in within the category.  Here is an example of our attempt to do this:

var sc = nlapiLoadRecord('sitecategory', 998821);  
var item_count = sc.getLineItemCount('item');
// returns item_count = -1

We have been able to retrieve the list of items within a category however the order is not preserved.  Here is an example of that:

var icol = [ new nlobjSearchColumn('storedisplayname') ];
var iflt = [ new nlobjSearchFilter('category', null, 'anyof', [ 998821 ]) ];
var irslt = nlapiSearchRecord('item',null,iflt, icol);
// returns irslt.length = 200

Our use case is we would like to implement client-side faceting and paging but need to return the entire list of items in a given category from a Suitelet to do this.