Select2 selected tag as object instead of 'id' in Knockout

So I have a select2 tag input working fine, displaying the tags correctly and storing the selected id in the selectedProducts observableArray. However, my HTTPPost is expecting an array of objects, not an array of integers. I was looking for how I can store select2 as an object (eg {id: 1, text: "abc"}) instead of an array of integers.

My binding is below:

<div class="col-sm-10">
    <input type="hidden" id="tags" class="select2 form-control" multiple="multiple" data-bind="value: selectedProducts, select2: {tags: ko.toJS($parent.availableProducts), placeholder: 'select products'}" />
    <pre data-bind="text: ko.toJSON(products, null, 2)"></pre>   
</div>           

var newItem = function (newitem) {
    var self = this;

    self.id = ko.observable();  
    self.selectedProducts = ko.observableArray();
    self.products = ko.computed(function () {
        return self.selectedProducts().split(',');
    }, self);
}       

var viewModel = function (data) {
    var self = this;
    self.newitem= ko.observable(new newItem());    
    self.availableProducts = ko.observableArray([]);      
    $.ajax({
        type: "GET",
        url: '/GetAllProducts',
        dataType: 'json',
        contentType: "application/json; charset=utf-8",
        async: false,
        success: function (data) {
            ko.mapping.fromJS(data, {}, self.availableProducts);
        },
        error: function (err) {
            alert(err.status + " : " + err.statusText);
        }
    });       
}
ko.bindingHandlers.select2 = {
    init: function (element, valueAccessor, allBindingsAccessor) {
        var obj = valueAccessor(),
          allBindings = allBindingsAccessor(),
          lookupKey = allBindings.lookupKey;

        setTimeout(function () {
            $(element).select2(obj);
        }, 0);

        if (lookupKey) {
            var value = ko.utils.unwrapObservable(allBindings.value);
            $(element).select2('data', ko.utils.arrayFirst(obj.data.results, function (item) {
                return item[lookupKey] === value;
            }));
        }

        ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
            $(element).select2('destroy');
        });
    },
    update: function (element) {
        $(element).trigger('change');
    }
}