I think ive found a good deal with 1&1 (http://order.1and1.co.uk) for 25 *.info domain names free and £1.99/year (Min. 2 year) for *.co.uk domains.
But this is where I have the confusion
If I setup a domain using the above company can you point this to a subdomain http://www.username.plus.com/domain/ on plusnet? Do plusnet also want paying? or can you only point domains at the root locations ie www.username.plus.com?