The 50/200 is the saltwater/deepwater version. You probably don't need that.
The "Gold" version isn't about the transducer, but rather indicates that a Navionics mapping card is included in the package.
Here are the options for the 7 along with MSRP:
No transducer 000-10970-001 $599 83/200 + 455/800 HDI 000-10966-001 $699 83/200 + 455/800 HDI + Gold Pkg 000-11051-001 $769 83/200 + 455/800 HDI + CMAP Max-N (Latin America ONLY) 000-10966-006 $899 50/200 + 455/800 HDI 000-10967-001 $799 50/200 + 455/800 HDI + Gold Pkg 000-10972-001 $869 50/200 + 455/800 HDI + CMAP Max-N (Latin America ONLY) 000-10967-006 $899 No transducer + CMAP Max-N (Latin American ONLY) 000-10970-004 $699
I suspect you'll want the 000-10966-001