How to choose the best programme for MS in thermal sciences

[inanimate]

Hi guys, first post here, so I hope I get some replies. Im an international student, and have got admission into the MS programmes in mechanical engineering at UIUC and Purdue. I am also quite sure that i'll receive an admit from michigan and georgia tech. The question now is, that based on my interest in thermal sciences, how should I choose between them assuming:

a ) I dont get an RAship from UIUC

b ) I get an RAship from UIUC (to explain, I might get an RAship from UIUC )

Thus the second question: if I dont secure an RAship now, what is the probability of securing an RAship or TAship, once I join one of the universities.

Any thermal seniors who might be able to guide me would be welcome....