I have 6 of the original $7 or so Home Depot lights on my rack in the basement. These have the 'good' ballasts that were suggested years ago when I bought them.

The fixtures have (I believe) 40 watt T-12s.

I need two new fixtures and the ones I own are unavailable for purchase. I have added an additional shelf to the growing platform (woo hoo, more plants).

Two questions:

1. What fixture should I buy (best 4' x two fixtures bang for the buck)?
2. I believe my current fixtures take a variety of bulbs - should I replace the T12s with something else or new T12s (they are getting long in the tooth and are probably putting out a lot less light than they did when new)?

Thanks