Are these safe to run from new or is it best to get a few miles on the clock first? Think I'll be ordering one in the next few weeks ready for when the car is shipped over
IMO I would say you are better off waiting until you have clocked a few miles up first, there are two reasons for this.
1. Seat recomend a 'running in period' this is seen as a bit old hat now and some withh argue that the endinge should be ready to rock and roll at time of delivery and some even belive that 'all engines are run it at the factory', whatever the truth may be the fact is that in the owners manual there are very specific guildelines for the 'running in' of the engine and I feel if you want to get the best from the engine that you are probably best to take note of this advice.
2. Its nice to get to know your engine and its limits BEFORE installing the box so that you can see just how much of a difference the box makes. Otherwise the only time you will see any actual change is when you take the box off and you see the losses that come with doing that.
It shouldn't take long to clock up 1000 miles and at least if you do that you will have a little piece of mind you will have less chance of damaging any parts of the engine that aren't yet properly worn/seated in.