Database generation of active US domains

I want you to build a system to generate a database of all active NL-domain names and in the future of other TLD's. When the basic dbase is build, the dbase has to be updated every ones a week. There are a couple of options I can think off to get this dbase to consist of 98% of the active NL-domains. 1. making use of a search engine that starts indexing via a directory like DMOZ, following all links it can find. I estimate that this will gather 60% of all active NL domains and will take about a month . The search engine can run on my own server; 2. reading the whois. I don't know how though; 3. making use of DNS-service. I don't know how though; 4. command line pinging based on a dictionary file. When the dictionary is pinged 5. brute force commmand line pinging can be the next thing to try. Starting with [login to view URL] > [login to view URL] > et cetera; These a just some of my suggestions/ideas but for sure you will have way better ideas to collect this dbase of active domain names. Just the dbase of NL-domains would be great, but it would be even better to collect also IP-address, pagerank of the domain, whois info etc. This is absolutely not necessary though. I prefer working with someone who can show proof of his/her expertise. Don't send me any general reactions that you send to every posting. When responding please supply me with your ideas on this topic and a short plan of action that you will take. I'm really looking forward for your swift (re)action, Henry