i have
twin Garmin GPSMAP 8412xsv
Garmin GSD26 depthsounder blackbox (still to be installed)
one B265LH transducer
one GRM Fantom 18x dome radar
old Raymarine VHF (i will change that soon with probably a Garmin VHF215 AIS to read AIS targets)
Fusion stereo with amp
Reactor 40 Autopilot
Freedom 235 for slight off shore use
What electronics you need depend on several factors
Garmin does just fine, the GPSMAP series is superior to the ECHOMAP series but more expensive
- If you don't boat at night and fog is highly unlikely then you don't need a radar
- If you don't fish then a much more economic and basic MFD is more than enough
- If you fish shallow and or want to discover new submerged structures for fishing or diving then a side-scan transducer is a great tool
- Autopilot is nice for long trips or fishing alone, for short trips not really needed
- AIS receiver is nice to have if you boat in a crowded area, some VHF have a built in receiver what show targets on the map
For slight offshore use in a sunny area and no night boating and not advanced fishing i would suggest
1 or 2 MFD's in the size to fit your console, two smaller MFD's are better than one big
1 transducer according to your use, only boating or also fishing will decide what model
1 VHF radio with a good antenna
A complete set of flares, smoke buoys, a mirror, live vests, throwables, extinguishers, etc, according to your local laws
Without more information about more detailed informations regarding the intended use it's difficult to be more detailed.
Chris