Stick with simple, simple is good.
A couple of suggestions though. You have a lot of aligned "center" content that looks kinda odd, especially with bullet points.
The big icons on the home page would be nice if they were clickable to somewhere with info about what those things are.
Drop the forum, it really is not needed for a small provider. And if you do keep it, make it simple. SoftLayer for example only has 3 public categories listed. http://forums.softlayer.com/
So stick with simple even on the forum.
cPanel login on your main site can be good and bad. It shows that you're a small company with one server. Same goes for the webmail and WHM. For example if you had 2 or 3 servers or hundreds. Then those obviously would not work for anybody except users on your first server listed there. It also shows that your website is listed on the same servers as your client. As opposed to it being secured on it's own server, not mingling with client data.
The news page might be nicer if you found a way to not use that integrated facebook plugin thing. But rather something that blended with the site better. That looks pasted on, vs integrated/streamlined looking.
The header of your site might look nicer if it matches the width of the body. Then make the header on the WHMCS side, match the width of the WHMCS system. They can be different widths, it just looks better in my opinion if it matches the body of the page. Otherwise the integration is clean and simple, which is good.
Also make your Morgan logo clickable to return to the home page.
To put the copyright watermark, it should be © in the html code. Though that's not a big deal I guess.
I'd dump the IRC and grab a live chat solution. Since you're a single person shop zopim would be a good start. http://www.zopim.com/
All of your features are on the main page. http://morganwebhosting.co.uk/hosting.html
So there is no need to duplicate those features in the cart, except for the plan details like storage/bandwidth/price. You should also put the price on the hosting page.
These are just suggestions off the top of my head. I recently had our site for AH reworked so ideas are still bubbling in my brain. At any rate, make sure you're at least enjoying the challenge.
I also see that you're a fan of http://www.iconfinder.com/