Embarcadero has released a new Instant Trial for Delphi only and that includes a trial version of FireDAC. You can get the instant trial (or the regular download trial) form www.embarcadero.com/products/delphi/downloads. In both cases, this is different from the previous trial, which was for the full RAD Studio product.
What is an Instant Trial? It is ready-to-use image of the installed application, based on Embarcadero's AppWave technology. The application (in this case Delphi) is streamed to your system but you can start using it while it is being downloaded. The only caveat is that initially you get only some features (for example the iOS compiler) but you'll have to wait for others (like the Win32 compiler). If you use a missing feature, your command will have to wait until the related portion of the program is downloaded. More information is available at www.embarcadero.com/press-releases/embarcadero-instant-trial-of-rad-studio-xe4-lets-developers-build-ios-apps-in-minutes.
A big advantage of the Instant Trial is that it is executed on a virtualized environment, so all you get on your system is a single file, nothing gets under Program Files, you have no changes to the registry, and deleting it will be very safe (and also, installing it alongside an existing Delphi won't affect it in any way).
Given we are streaming an application installed on a system, what we could do was install also FireDAC (for which there isn't a separate beta). In other words, Delphi XE4 Instant Trial is the way to have a fully working FireDAC trial version. But the Instant trial overall is faster to install, easier (no need to go through all of the options), separate from your code... and that makes it a great option anyway.
Moreover, for testing iOS development without a Mac, you can refer to MacInACloud and the specific offer related with Delphi trial, more details on blogs.embarcadero.com/jtembarcadero/2013/05/24/macincloudcom-special-offer-for-rad-studio-users-a-24-hours-over-30-days-trial-period/.