JarCastingui-select-infinity 
Extend ui-select with feature of infinity scrolling.
Installing
bower install --save ui-select-infinity
Example
angular
.module('SomeModule', ['ui-select-infinity'])
.controller('SomeCtrl', function ($scope, $q) {
var loadingItem = {type: 'loading'},
hasNextChunk = true,
queryString = '';
function getInfinityScrollChunk(id) {
//implement your lazy data request here
}
function addLoadingStateItem() {
$scope.collections.push(loadingItem);
}
function removeLoadingStateItem() {
var index = $scope.collections.indexOf(loadingItem);
if (index < 0) {
return;
}
$scope.collections.splice(index, 1);
}
$scope.isItemMatch = function($select) {
//implement your match function here by $select.search
};
$scope.requestMoreItems = function() {
if ($scope.isRequestMoreItems || !hasNextChunk) {
return $q.reject();
}
addLoadingStateItem();
$scope.isRequestMoreItems = true;
return getInfinityScrollChunk(nextChunkId)
.then(function(newItems) {
nextChunkId = newItems.nextId;
$scope.items = $scope.items.concat($scope.newItems.items);
return newItems;
}, function(err) {
return $q.reject(err);
})
.finally(function() {
removeLoadingStateItem();
$scope.isRequestMoreItems = false;
});
};
$scope.refreshList = function() {
queryString = query;
};
});
<ui-select reach-infinity="requestMoreItems()">
<ui-select-match placeholder="{{placeholder}}">
{{$select.selected.name}}
</ui-select-match>
<ui-select-choices refresh="refreshList($select.search)"
refresh-delay="250"
repeat="item in items | filter: isItemMatch($select) track by item.id"
ui-disable-choice="collection.disabled">
<span ng-switch="item.type">
<span ng-switch-when="loading" style="height: 48px;line-height: 48px">
<i>loading ...</i>
</span>
<span ng-switch-when="any">
{{item.name}}
</span>
</span>
</ui-select-choices>
</ui-select>