Selenium is good enough for this purpose...You can probably use waits() for the results to become available in the DOM. So you can use Selenium to test REST calls especially if your results update the HTML displayed on the page. Refer to this:
WebDriver driver = new FirefoxDriver();
driver.get("http://somedomain/url_that_delays_loading");
WebElement myDynamicElement = (new WebDriverWait(driver, 10))
.until(ExpectedConditions.presenceOfElementLocated(By.id("myDynamicElement")));