The fastest method is to pay with a credit card via PayPal after you accept the job. This will instantly start the data retrieval process. We can also provide an invoice. If the invoice is being sent through a university, there may be a delay in processing because of possible university-specific administrative requirements to add Texifter as a vendor.
The free trial of DiscoverText is self-serve: http://discovertext.com/start-a-free-trial/.
Also see the FAQ: When can I expect to receive Sifter data paid for via PayPal?