Very sure that works fine and you could swap them within a few minutes. The 300 simply has stronger drivers and is capable of running drive units at 12V or 24V. So going from a type 100 to a type 300 should always be fine.
Raymarine have loads of on-line manuals <A target="_blank" HREF=http://www.raymarine.com/raymarine/Default.asp?site=1&SECTion=3&Page=171&Parent=166>Here</A>.