If yuo cn stretch to an extra £60 or so on each bike it will get more for your money. At the sort of budget you are on I'd be inclined to stick to a rigid bike as you will get a better level of of components on it.

Got my missus a Specialised for just under £300 and it's a nice all rounder. Nothing amasing but perfectly good for some fun on the local trails.

You can always add suspension forks at a later date