If all else fails, you can buy the components separatly. I did just this a couple weeks ago.
Panel with circuts breakers, indicator lights, reverse polarity protection and voltage meter - $130
SS shorepower plug- $95
GFI outlet and box- $25
On-board 3 stage dual battery charger $100
Marine grade wiring- $40
50' Shorepower cord- $55
Worst part was drilling the hole for the plug.
Made an adapter to plug in while in the garage, sweeet!