More Questions about Lake Maps

Lake Maps
Guys, I need your help. Over the last several months I’ve been purchasing “stuff” to set my boat up for spider rigging. Have purchased the Helix 7G3NSI; the Terrova Ipilot Link.

I’m overwhelmed by maps. LakeMaster V offers four levels: LakeMaster; LakeMaster Plus; Smart Strike and Contour Elite. Then there are other brands and there are always the self-made maps by knowledgeable Outdoor Boarders. I will predominately fish Lake Erling in Southwest AR. The lake is relatively small but it does have lots of structure (Bodcaw Channel).

Using LakeMaster as an example, there are charted lakes and then there are high-definitions lakes. Lake Erling is off the beaten path and it is NOT a high definition lake. (Seems silly to by maps for multiple states when I only want one lake – ah – the blessing of technology)
As mentioned, I am crappie (white perch) fishing. I need to “see” the old creeks and sloughs identified where I can hunt/ find ledges/drop offs in close proximity.

With all that said in this wall of text, if you were buying a lake card that was compatible with Helix and I Pilot what features would you look for or better yet purchase?
Thanks in advance