So I've have had a great response about potential new buildings. A warehouse on Arkwright Rd potentially looks great, see details here (thanks Shelley!) Having spoken to the agents and Reading Borough Council, it seems as though it's in a 'designated corridor' where RBC are highly unlikely to grant change of use.
So two things are now very clear to me: #1 This is going to take a lot of work to figure all this out. #2 We need a small team to help do this.
So if you like this kind of thing, are happy to do research / make phone calls, could you let me know! I now have more building details than time to look at them!