Your speakers will be fine; so too your monitor - that's the good news.
Not so good will be the chances of getting both a PC and laptop for the price.
For about £600 you will get a good PC with plenty of RAM and storage space and a fast processor. Together they will get you going for video editing.
The laptop is where it all falls down - a capable video editor will cost most of your budget.
A compromise might be to get an external hard drive which can save some of your data and share it between the PC and notebook.
Having said that, there are some smart forum users out there who may well come up with the goods :-)