Jmeter thread per url

I have one project to test load balancers algorithms for web cluster and I decide to use Jmeter but am stuck since am not experienced with it and on Internet I see different cases and scenarios which are not detailed described (steps hot to achieve them).

In test environment I have 5 generic websites (web1.com, web2.com, web3.com, web4.com and web5.com).

Test cases which I want to perform are:

CASE1: Linear and proportional web load - by other words I want to check web1 5 times in row then web1 and web2 5x, then web1,web2, web3 5x, then, web1-4 5x and then on the end all 5 websites 5x. To see how computer recurses and web nodes will perform in this proportional load. As far as I know this should be done by 5 different threads but I cant define URL per website or time when it will start to load other websites as well. I have tried with dataset (cvs) but I can achieve that parallel website check because in CVS I can only add one website under another as list...

CASE2: In this case I would like to set my own "random numbers" for example to send website check in "random order": web2,web2,web5,web1,web3,web4,web1,web1 ... Reason for this is because I want to simulate "real case" by other words real "clicks by end users" which are not linear... (I want to keep "random list" because I want to perform same random check on several different LB algorithms).

I would be very great full if you have any described steps or any screen shots.

Thanks a lot!