I personally would never let my fighters wear 14oz gloves to spar unless they are very small guys.
Reason being is because it's good to work out with them so when you do put on the fight gloves, they feel like you have nothing on you're hands.
Don't do the Gel titles, they are very heavy. A good pair of sparring gloves that are lighter are the Winnings but they are very expensive, like $500.
For me, the new IMF Ringsides are great for the price and are lighter than the avg sparring glove. Try those out.