a-site-users-first-last.js

var usersUrl = "/_api/Web/SiteUsers";
function getItem(res) {
  return res.data.value;
}
$q.all({
  first: $http.get(usersUrl, { params: { $orderBy: "ID", $top: 1, $select: "Id" }}).then(getItem),
  last: $http.get(usersUrl, { params: { $orderBy: "ID desc", $top: 1, $select: "Id" }}).then(getItem)
}).then(function(res){
  console.log(res.first[0].Id, res.last[0].Id);
});

full-example.js

// !!! UPDATE !!!
// New full example using Angular and lodash

var usersUrl = "/_api/Web/SiteUsers";
function getItem(res) {
  return res.data.value[0].Id;
}
var q = { params: { $orderBy: "Id", $top: 1, $select: "Id", $filter: "Id le 100000" }};

$q.all({
  first: $http.get(usersUrl, q).then(getItem),
  last: $http.get(usersUrl, _.defaultsDeep({ params: { $orderBy: "Id desc" }}, q)).then(getItem)
}).then(function(res){
  var idPool = _.range(res.first, res.last + 1);
  return _().range(5).map(function(i) {
    var idIndex = _.random(idPool.length - 1);
    return idPool.splice(idIndex, 1)[0];
  }).value();
}).then(function(fiveRandomIds) {
  console.log(fiveRandomIds);
});