I don't think you need more height. If you added more height with larger candle holders then it would overwhelm the leis which is the unique feature to your table. You may want to add some type of color contrast like they did here with a runner under the candles and leis so they pop.
Re: Need opinions
Also, definitely go with the battery-operated candles. You may not like the idea, but it's a lot better than having half of your candles blown out.