£30 and you've got yourself a T8 floro x2 tube, perfect for your seedlings, or a 125w cfl enviro.
with them 2 options above, not only can you hang the light within a few inches of the plant, but it is in the blue 6400k range, which will seriously stop the stretch issue.
hps will stretch them like crazy as is already evident.
lighting is your biggest issue here, if they carry on like they are it's possible when they start to veg out they will just topple as the stem will not support the growth.