This year we bought a 5 shelves chrome rack where we can start more seeds with proper growing light system.  We use a shop light with T8 tube.  Rack is about $70 and light system about $110.  We can now start 4 seed trays at a time.

This is the seed growing rack.
Tomatoes. We have black zebra, banana leg, pink brandy, winter goldkeeper and black cherry.
Peppers growing very very slow. I believe I would need a heating mat for them.
Cabbage, broccoli and kale.
Yellow and green zucchini.