Hi

Try looking at RedFox Hosting.
They do a reseller package that gives you 25 SQL conns, 100 domains and a powerful "ISP" control interfaces (Helm(you will love this)) . 18.95 pcm !!.  

Actually the Helm interface alone is worth the money. Imagine never having to ask your isp to do anything for you as you can do it all yourself and you can add your own clients and assign domain settings access.  Effectively you are the ISP.

I have been with them for two years. I have around 20 dnn sites there. EG http://www.royal-southern.co.uk/ 
I have clients signed up to packages in their own right.

The tech support is VERY good, they are mainly a MS hosting company. Uptime is excellent.  

The one issue (common to most shared hosting) may be the worker process recycle time is set to one hour but they are about to start a service with only about 20 domains per server with the wp set to 24 hours.
 
IMO: RFH are the only real hosting company in the UK that cater for DNN and DNNers simply by virtue of SQL conns and the control you get.

You can sign up for a month and check them out.
Happy to help anyone doing DNN there if I can.

Hooray !

Ian