xbt,pjiang,or radiology please help: Do I need to file another 4

Hi xbt,pjiang,or radiology,

I just filed NIW-140+485. I am now trying to see whether I should think of filing an EB1a when it is current say in October.

Can you help me to clarify one basic question:
If I file an EB1a 140, do I need to file another 485 or I can link it to the 485 I just filed together with my NIW-140??

Originally I thought that I can link an newly filed EB1a-140 to my already filed NIW-485, then that 485 will be more secure. But I am note sure about this now. If I have to file a new 485 for an EB1a, then it seems not so necessary to file Eb1a at this moment, except that EB1a 140 will be processed a little faster. But an EB1a-485 is not processed faster than a NIW-485, right?

Thanks a lot in advance !!