I already did it, but thanks very much for the tickler.

In hind sight I should have ordered the TerraFix (for somewhere else - since Aeromedix doesn't sell the TerraFix). The AeroFix comes with a bulkhead fastener and a GPS connector cable with bare wire ends (Doug's description warned me, but I didn't think about it). I ended up contacting ACR and ordering the belt-holster and GPS cable with the serial connector separately that normally would have come with the TerraFix. Oh well.