HDS will run the Platinum+ charts.
The SonarCharts layer (presently called FishnChip in the Lowrance menu, I believe) is the 1' contour data that really helps identify good spots to target. You can now upload sonar logs to Navionics and they'll turn them into additional updated data in this layer within 24 hours. Simply do a Freshest Data update to your card and the new charting is viewable.
As to organizing waypoints and such, there's a ton of software out there available. I hear good stuff about the programs from Fugawi.
The Navionics chips come with a free year of Freshest Data updates, but also their PC App for free...and it does have the ability to import/export routes and markers so you can transfer to your plotter...and will sync to the changes you make on Navionics mobile apps as well.