I made my own 1.5" longer at the bottom. Originally I used a brake from work to bend the bottom flange but it had too tight a radius and that cracked..I just riveted a piece of 3/4" x 1/16" angle to the bottom back side and that worked great.
I got the panel blank from ACS. On the order I told them I wanted to use this for a panel and to make sure they sent me a straight piece with no scratches and that is exactly what they did.
A side benefit to having a longer panel was that I was able to mount my Stein vents directly in the panel. It was tricky getting the ears to go around the canopy decks and to get the panel in and out while clearing the spar bulkhead doublers (panel has to go in at an angle and with the radio's and map box extending thru the subpanel, this is a bit hard) but I was able to do it.
You can also put your control cables in the panel but if you ever want to pull the panel, you have to disconnect them from the engine. It also makes them a little tight because the stock bracket is recessed some back under the panel.