Its not recommended to mix the seed pods on the same unit, tomatoes and lettuce, you'll have to buy 2 units. Last year we used 2 red and 2 yellow cherry tomatoes on one unit.
This is a big deterrent for me - I'd want to grow salad greens, herbs, and tomatoes and I don't have the $$$ or space for 3 units (even at Amazon's cheap price now - $100 (ish). I'm sure I could do cherry tomatoes and jalapeño peppers since they are sold together (salsa kit) - but not cherry tomatoes and salad greens, then?
After the winter we replanted 2 plants out side in a flower pot and had tomatoes the rest of the summer. The other 2 plants where destroyed when removing them from the system.
Tomatoes do so well here I could easily bypass the whole aerogarden thing BUT - mics and rats eat all of the tomatoes before they ripen.

I've considered building a cage for the plants but it would have to be HUGE considering how well they do here.
Even basil and rosemary do exceptionally well outside here.
You want the biggest system they offer, we have the 7 hole stainless steel one with 2 lights. One light burned out in the first week. I called customer server and had no problems the rest of the year.
They plants keep growing and crowd out the lights after a few months on the unit we got.
Now Amazon has the 7 pot one (I think) for about $100 - that price is better than great. You can get that, two replacement bulbs, and the cherry tomato seed kit for $150 (they have good prices on a lot of their seed kits).
I cant remember what seed kits come with the unit we got. You can ( we did) order more seed kits and the fertilizer pills at a extra cost.
Most seem to come with the standard herb kit, unless you buy one of the specialty ones (chef's kit etc.). I've noticed some say "compatible with...." on them - I guess I'll need to pay attention to this.
Too bad I missed out on these when Linens and Things went out of business - they were always over-stocked on these things.