Root Any rom I have installed/Navionics not compatible!

I have installed the tegav2 roms (2.2, 2.3, 3.2 and 4.0) and whatever one i try when i go to google play the store says incompatible with the device. I run the app on my HTC Desire S fine.

I want to use the VP10 as a chart plotter on my small boat but need to get navionics working. I will purchase a USB GPS antennae for it too. assuming this will work???

what version of the x86 rom should i install which would work with the app?

many thanks