I was wondering whether that could be done! Would be keen to see a photo of the finished product if you have one handy.
I found a "Nissan skyline v35 second edition audio fascia panel" locally on Gumtree for $450 that would fit. It's got no "dual" climate button though (not that it's a huge deal breaker).
To be honest I'd be perfectly happy with just AUX input (if possible) and reverse cam via the existing screen. I literally only used those two features in my company car ('17 Mitsubishi ASX) while I had it. Never listened to radio, CD, or used GPS.