Why do you need a dedicated server right now ? Your forum is pretty small, if you don't have some heavy scripts on your site it's a waste of money. Your slow perfomance with fireboard has nothing to do with shared servers. Sure the performance with a dedicated server is way better and eventually, as the forum grows, you need to move to a dedicated server,but do you really need that right now ? As i see your site you don't but if money are not a problem then a dedicated server it's a grea idea.

excellent, I think I'll go for that one. I have got a package with a company called inventive hosting but I get nothing but problems from them so we still save some money stopping my subscription. So if I get this new package with go daddy, should I move the domain to them as well, or would it be okay to leave it with dreamhost since that is where I purchased it from?

finally, I have any used joomlacloner once and that was only testing, should I change name servers once I've got the package and then make a clone and transfer it?

Yes I would move the domain. Much easier if you can administer everything in one place. GoDaddy has a decent online help system that will walk you thorugh the how to.

For the switch, I would inform your users that it will happen starting day/time of your choice. I would let them know that the board will stay up but any posts made after that might be lost.
Take a snapshot and move it over to the new server.
Once installed, flip the DNS servers. It will take a little time. Most of the time ist 1-2h but it can take up to 24 (official SLA). I opt o do this kind of work in the middle of the night when there are little to no users on the forum.
Next morning they all wake up to a super fast forum. - at least in theory. Might want to do some reading up front and print out the articles on how to setup the domains and name servers.
DO a dry run by taking a snapshot of your site and install it on the new server. You can always delete it and start over. Just to make sure you don't run into unexpected issues. And as always: backup, backup, backup before making any changes.

Hope this helps!

You don't have to move the domains to godaddy if you buy a hosting package, just change the nameservers and it's ok. It doesn't matter from where you purchased your domains.
As for joomla cloner i didn't use it but I don't think that changing the nameservers have anything to do with it.

I just realized that it was £58 a month rather than $58 so that twice as much as I really wanted to spend.

Okay, if I go daddy and choose a Linux package but on shared hosting, do you think the forum will run faster than it does at the moment? I think you're right, my particular website gets something around 700 hits a day, however the website isn't the issue, it's forum that is running slow.

if you check the link, I am quite interested in the premium plan, and it's a hell of a lot cheaper.

www.godaddy.com/gdshop/hosting/shared.asp?ci=9009

whenever I get my.co.uk domains, I always have to point dream host name servers to the place I bought the domain,

I have just realised that DreamHost is indeed a Linux and not Windows. So there doesn't really see any point in me going to go daddy since I was only going to do it because of Linux. So it's back to square one, my forum is still slow even though it is on Linux

Debian Linux Wiki Link
Debian is the distribution of the Linux operating system we use on all of our servers. It is the "open source" distribution, run by a volunteer organization rather than a company. We have found it to have the best software packaging solution and highest stability of all Linux distributions and we love it to death! We also have a few OpenBSD machines running as firewalls. We have no Windows NT/2000 servers of any kind. We find them to be too insecure, unstable, inflexible, and expensive for our needs as a premiere hosting provider!

Linux or Windows, it doesn't matter.
What you don't understand is that your problem is not about Linux or Windows, Debian or Fedora or whatever 100 ditros out there.

If you wanna keep your host provider you should send them a mail, call or bang at their door, state your problem and ask them to fix THE MACHINE (named THE server) hosting your db, files, etc.

So once again, CALL SUPPORT!

I have been talking to my host and hopefully they'll get them to have a look at the error log. However, he was talking about something in my database that was 35 MB, apparently it took up two thirds of the whole database. I'm not sure what the table is, maybe somebody could tell me, jos_bb2_log. They reckon if I trimmed it, it would help. However, I need to know what to does before I do anything

bad behavior mambot is responsible for this table. just log data, you can safely empty it.