I had my aspen updated 2 years ago to the max unit. It's a lot better with a zillion pixels and faster refresh rate.It also plays really well with the Stec3100.
I do this all the time. From the north go to 6500 from the south I go to 5500 and they let you in everytime. They are busy and quick on the radio. Listen carefully and reply quickly. Have fun.
I have the Aspen Pro Max with the RC Allen 3 inch back up and took my vacuum system out. It's all you need as the RC has a back up battery and is cheaper. The Aspen max is reliable so I wouldn't go over board on the back up thing. You'll be fine.
I walked from the Garmin building at OSH this year and went through bendix king on the way to the A hanger. The Garmin building was so crowded you couldn't move. Not one customer in the BK building. Not one! Enough said.
Just order them on spruce. They will come in a reasonable time frame. That's what I did otherwise you'll never get one if you keep waiting for them to become available.
Keep the 440. I have an IFD 550 in my aircraft and it is incredible. Get the I-pad app and learn it as you will come to like it and it's ease of use. There will be no home key pushing to get back to a place you forgot how to get back to.
I have an Aspen PFD and just had the vacuum system removed completely with the installation of the RC Allen 2610-3. That is your best bet. $2795.00 from Spruce.