Hi,
Sorry to hear contracting work has been harder to come by lately but that's great news about the job offer, congratulations!
You've got a few options for your company if you decide to take them up on their offer:
You can leave your company active and continue to do the odd bit of contracting work as and when you want to. If you do this, you'll still need to make sure you stay on top of filing responsibilities for your company.
Put your company into dormancy. Meaning your company is in a sort of hibernation. It'll still exist but you'll have fewer filing responsibilities as you can close down things like your PAYE scheme and de-register for VAT (if applicable). You can re-activate your company at any time if you want to use it again.
You can close your company down. Depending on how much money your company has, you may want to get advice on closing via voluntary strike-off or MVL.
The first two options are good if you're not 100% sure about what you want to do just yet. It gives you a chance to see how you like your job first, in case you change your mind and want to return to contracting. If you want some more resources to help find more contracting jobs, Crunch has a jobs board and also this article about some of the best freelancing sites.
Hope this helps!