I am working with that kind of hardware. If Adventure folks will just tell me what their interface requirements are, we could all have the ADS-B in, and AHARS, and WAAS GPS capability for less than $150. We'd have weather, partial view of other planes in the area, more accurate GPS data, RAIM style GPS, and more, IF Adventure Pilot folks would just tell us what their software needs. Yes, i know they make a buck from the units they sell but the folks that do "homemade" has a really small intersection with the ones that buy the $1,400-40,000+ equipment to do the same thing, so AP won't lose any money anyway.
<sigh>