They're definitely stretching "for the light".
Have you got a small fan on them? If not I'd suggest an 80mm or 120mm PC fan at this stage to help strengthen up the stems. <<Oops clearly I didn't read your post properly!
Also you'll prob want to move the light a little closer - the general rule is, if it's too hot for your hand, it's too hot for your plants - so keep moving the light until it's warmish to your hand but not hot - remember you'll need to move the light once, even twice a day as they grow.
I'd consider transplanting them into taller pots and burying them a little deeper and getting a fan on them asap. If you don't transplant them I'd at least fill those containers up to the top with soil to cover some of the spindly stem.