Paul is right as usual.....
Right now, the only EFIS's I'm aware of the work well with those boxes are the GRT, Chelton, OP & Avidyne.
GRT is unique in that it can accept both the analog and ARINC inputs simultaneously (one to each screen), or via serial from a radio like the SL-30...or all three at once, along with multiple GPS inputs. At the moment, GRT / OP are the only ones I know of with this many inputs. Earlier this year we did an RV-10 panel that had a GNS-480 with the serial GPS, ARINC NAV & Analog NAV, along with an SL-30 (both Comm & Nav interlink), and an external GPS along with the GRT internal GPS...ALL hooked into the GRT...with TWO AHRS boxes. That means this guy had THREE GPS inputs, THREE NAV inputs (from 2 radios) and one comm interlink, EIS & OAT inputs along with the XM weather and two AHRS boxes all running into the GRT and plumbed out to a TruTrak AP. (we had to use three GRT screens because we just wouldn't have had enough inputs using only 2 screens. Luckly the software behind the GRT stuff is really powerful, so you can do that).
Setup/programming was kind of a nightmare (because we used up EVERY SINGLE port that GRT had available across all 3 screens), but once done it's a mighty powerful tool.
Anyway, to get much use with the EFIS and a Garmin box, right now GRT is ahead of the pack....but me thinks that AFS, Dynon and others are not far behind.
Cheers,
Stein.