What tools are used to predict the products of a chemical reaction?
I don't know for sure, but I suspect these two reagents would lead to the same product.  They are both superacids, and extremely harsh.

Whichever is a better Bronsted acid (proton donor) in benzene probably leads to a faster reaction, or better conversion.  But who knows?  Maybe the reactions are so acidic (two plus charges in a small organic molecule!) that they are just about the same.

There may be some superacid expert lurking on chemistry.se who knows this answer, but I think the only way to know is to do the reaction. 

You may also want to write the corresponding author of the paper. They may already know the answer. Or, they might be flattered and may find the question interesting enough to go to the lab and do the experiment.

(I don't think computational chemistry will help here.)