The only problem is, according to industry insiders, C129 and C145 are mutually exclusive. Despite the best efforts of GPS manufacturers, unless something changes, no panel-mounted GPS currently installed will be easily converted to the new standards. Sports fans, the GPS you buy today will work tomorrow just as well. But don t count on it to be able to meet the new requirements. Buy a GPS to match your other avionics.
Some companies make great nav-comms.
Many make outstanding GPS systems. Others are known for audio or autopilots. If the mission for your avionics is to look nice, then you should buy the same brand. If your mission is to go from here to there, without spending a fortune, or getting lost, or having the lights go out in a multi-thousand dollar box, your choice should be based on performance and reputation. Not brand names or styling.