one more noob question haha when people say 400 grams per 1000 watt-do they mean only one plant under a 1k, or is it 1k stretches over a 5x5 area and a properly vegged/flowered plants can each pull 400 grams?
They mean total yield of total plants grown under that amount of light.
It could mean ONE plant, trained to have many many tops to increase yield and then kept in place with a horizontal trellis (ie "SCROG").
Or it could mean between 16-80 individual smaller plants, crown together into a little crop "forest", again to maximize yield (ie "Sea of Green").
Growing each way has its own pros and cons, which are beyond the scope of this post, but I'd hasten to add that you have to take any such published yield estimate with a gigantic grain of salt. How the plants are grown, and skill of the grower matter. . .a LOT.
But I have heard that TGA gear is not that great-and alot of people saying no to his stuff.
You'll hear mixed reviews on TGA.
In fact there is a 40+ long page thread on TGA ("are they stable") on this very board.
If you take the time to read through it, you'll hear a very broad cross-section of opinion on TGA, and why people like and/or don't like his genetics. Do that and you'll be pretty informed.
If you're too lazy to do it, the single biggest knock against TGA is that many of his lines are effectively unstabilized polyhybrids. He picks some elite strains or top lines, crosses then, does only a few generations of selection, then sells the offspring. This means that depending on the strain, the plants that grow out of any given pack of seeds are liable to have many different phenotypes, some excellent, some maybe not as excellent.
But if you're happy with what you have, that's all that really matters.
If you want to look at other brands for high quality seeds, its pretty hard to go wrong with any thing from Mr. Nice or Serious seeds just to name two of the more established houses.
Sannie has a great reputaton in terms of quality bang for the buck.
I'd also hasten to add here, that there is really no need to go for the "latest greatest" thing. Old standbys from 20+ years ago (Northern Lights, Blueberry, Bubblegum, AK-47, Skunk #1) are typically going to be easy to grow, and give good yields of high quality product.