I don't know specifically about any of the links you posted, but I purchased a lighting kit on eBay from amvona.com. I haven't used it much, but am pleased with the construction quality.
Here is a link to the kit I bought:
http://cgi.ebay.com/ws/eBayISAPI.dl...mMakeTrack=true
This was new equipment auctioned by amvona. They lists hundreds of items at a time (and the eBay selling prices are WAY below what the Amvona.com website lists). They have two different kits like this: one called a "Portrait" lighting kit, that has two, 1000w each softboxes, and the one I got, which is a "Product" lighting kit, with two, 500w each softboxes.
I decided on the smaller (2x500w) kit because: (a) I was just trying to get supplemental lighting to use inside a normal size room (not trying to light up a movie stage...), and (b) I was concerned that plugging in two thousand watts in most houses would blow a circuit breaker, unless you knew two outlets were not on the same circuit. (A typical 15 amp outlet is good for 1800 watts.)
I love the case -- it's nice to have a place to store everything (stands included). It's kind of heavy with everything in it, but it has wheels on one end. One person can certainly carry it, but rolling it is better.
I understand now that these Amvona kits are pretty much knockoffs of the Photoflex "Starlight" products.
Here is a link to the Amvona eBay store:
http://search.ebay.com/_W0QQfrppZ25...Zamvon aQ2ecom
Like any other eBay auction, you have to decide what you want to pay, and just have to keep watching auctions. Every couple of days, I would tediously go through all the listings in the Amvona ebay store, looking for the kit I was interested in. There would generally be two or three of this particular item auctioned off each week. For a couple weeks, I just kept "watching" the listings (on eBay, "watch this item") and getting an idea of how much the kits sold for. This one ranged from maybe $170 when somebody got a really good deal, to $200 or so dollars on average, to $300 or so on occasion. (The 2x1000w kits sell for more than that.)
The "real" bids always pop up in the last couple minutes before the auction ends, so an hour before the end of the auction you might see the bids at only $75, then a bunch of bids submitted at the last minute. Note that the prices I mentioned above do not include the additional $45 shipping.
I ended up paying about $221 + $45 shipping. (Got tired of watching, and decided to just get it over with...) But, that's still a pretty good price for two softboxes with 8-1/2' stands, a total of 8 bulbs (lots of spares), and that nice, big case to keep everything in. I think a week later the same kit sold for $180 or so (lucky guy...).
As I mentioned, the construction quality is pretty good. The softboxes are made out of a pretty heavy material -- kind of a "fake leather" vinyl or something type of feel (I don't know how to describe it, but its not like the lightweight nylon fabric that some softboxes are made from.) They have a shiny, silvery interior.
When I first set them up, at night, they seemed very bright and lit up the room very nicely. I was real pleased with the very nice, even light, and the soft shadows. However, if you turn them on in the daytime, they don't seem quite so bright, if that gives you any idea. So they will do great compared to just using interior lighting (but I have fairly dim house lighting), but they aren't going to light up a stage. You can always set them up and leave the front diffusion panels off, to get brighter light, but not as soft.
Also, the reason I got these lights was for a video project of interviewing my 79 year old parents, and getting some of their stories on tape. I think the 500w lights are about as bright as I'd want to go for that, to avoid having them squinting due to the lighting if I'd gotten the 1000w kits. But I guess that's all relative, and depends on how bright your ambient lighting is. In a daylit room, they don't seem so bright.
Also, these softboxes and ceramic bulb sockets *are* rated to handle the 1000w bulbs, so I could go brighter if I need to (by buying some 1000w bulbs).
Tim L