How much room do you have?
Immediate thought is to hang a shelf
above the current set up, get another shoplight fixture, and double your seed starting area without sacrificing/devoting more square footage.
I started out with a 4' plant light equipment that I'd originally given my dad, but I found it languishing in the basement so I took it back

When I ran out of space, I dug up some unused bracket shelf system and a couple of wire closet shelving from the back of the garage because, after staring at the plant light system for about 30 min. I realized that if I took it apart and put it back together again, I could push the two uprights supporting the hanging light fixture through the wire shelving after bending the wires open a little bit.
BIL found me a couple of shoplights and voila! I had 2.5X the original space because the extra fixture lit up a wider area. Of course, I'm running out of room again....
