My 10 gallon has 2 screw in type bulbs at about 15 watts each. They were listed as Daylight so can be anywhere from 5000-6500K and seem to do a decent job on my plants. I get slow growth but also not a lot of algae either which is nice. I don't add ferts to that tank, just water changes and fish food.
The screw in bulbs are a little less efficient than a straight tube, though not bad for smaller tanks. And very cost efficient.
Yes I bought plants without an employee there that knew anything about plants. BUT I also got them at the price of the cheapest SKU they had, "Water Lettuce" at $2.99 a bunch.
I don't think Ludwigia has one that I'm aware of. It's just... Ludwigia. Vallisneria species are all referred to as some sort of "Val" and the Bacopa is also known as Moneywort.
Oh, and I picked up the supplies today to do a DIY CO2, but I thought I already had a bag of sugar so I didn't get any, and obviously I didn't have any sugar at home. So that will wait till tomorrow now.