From your description, you may have a good chance in either of the two categories. Generally EB1a is harder however if you prepare your application carefully there is a good chance.
If your I-140 application is denied, you can always reapply and the new I-140 application is given the attention of a fresh application. So a denial would not directly affect the outcome of future applications.
Among EB2-NIW and EB1a, the former is generally easier.
In the case of your wife, EB2-NIW is very possible ( several publications, citations and important work which could be claimed to be of national interest one e.g: application to green technology, also can claim several other important applications of her work). EB1a may also be possible. She would have to look a USCIS criteria in EB1A and also make sure her work is regarded highly among peers. She could use citations (eg. using google citation index) and recommendation letters.
In short it is very much possible to self-petition with our packets. Lawyer or our packets would be your choice but in general, in either case there is more or less the same effort involved.
Best of luck
Green card for Phd Team
Helping NIW and EB1A applications
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