No but actually there is very little cost difference between an FIA seat and a non FIA seat so I'd go for one anyway. The other point is that you'll get the chance to race at Spa or in other countries and as such you'd be best having FIA approved equipment anyway. We've debated it ad infinitum but whilst at the moment the Blue Book doesn't require it, it won't be long before it does.
Race suits, fire extinguishers, harnesses are all coming into "line" anyway.
So, if you are building anew then plan for the future rather than obselesence.
Good luck BTW.