netsol is good for checking to see if the domain is available. Some others, (Dont know about the ones listed in this topic) remember the domain name you searched for and they buy it or raise the price of it for when you want to buy it later.
Then after you decide which domain name to use, go somewhere like www.bizmaxusa.com
or some other web hosting site to get hosting and buy the domain through them and you get the domain name sometimes cheaper. (Kinda like a package deal or something like that)