Yes, both Hightail and Dropbox Professional offer a Free Trial.
Hightail is designed for Large Enterprises, Medium Business and Small Business.
Dropbox Professional is designed for and undefined.
Pricing for Hightail Starts at $12/Month whereas for Dropbox Professional Starts at $9.99/Month when Billed Yearly.
Some top alternatives to Hightail includes ShareFile, Dropbox Business, Microsoft OneDrive for Business, Dropbox Professional, GoProof, Ziflow, Workgroups DaVinci Proof, WebProof, Dropbox Paper and Proofing.
Some top alternatives to Dropbox Professional includes CollaborateCloud, CloudFiles, Dropbox Business, FileCloud, ownCloud, MyDocsOnline, FilesAnywhere, DocUp, etfile and Dropbox Paper.