The Newer branded 180W light are good, bear in mind they will not be as powerful and offer as many features and those from the top brands like Profoto, Elinchrom and Bowens.
They are more than powerful for a medium size room if you are considering an home studio. If you use them within their limits you can obtain fantastic images.
13 of the of the shots in the modelling section of my website were taken with Neewer 180W flash heads.
http://www.redsnappa.net/5MODELS/models.htm
I would not recommend you buy this type of lighting as a kit from one single eBay store, the price is often more expensive than the cost of the component parts. It takes longer to build a kit that is suitable for the type of photography you want to do, but I would advice to source the flash heads, light stands, light modifiers who are doing the best deal at the time.
Buy and enjoy they are great for learning on as an amateur. When you sell them you outgrow and but and main brand flash you can still keep these to use as background\hair lights.
The major negative point with these newer Flash Heads is if they develop a fault that is it they cannot be repaired, an new unit will need to be purchased (£30 each it is not a massive hit to the wallet) I have had mine 3 years but I did treat them with kid gloves as I know the build quality obviously is not up to the standard set by the likes of Bowens Lencarta etc. Bear in mind though if you need to get the main brand flash heads repaired, you probably would be looking at a minimum price repair cost of £80 - £90
There are negatives and positives of everything in life, it is up to you if you are able to save up for main brand flashes, great, if your budget only stretches to the Neewer Flash heads then use them as a basic learning tool. until you can afford to buy the better flash heads.