Sid is bang on - wide choice, could be customised every which way and great service (no affiliation etc). Of course they have not been used yet ..... I did get some square aircraft style bezels from SpeedHut too but that would have made the pod wider at the bottom corners right where your legs want to be getting in and out.
The button on the tacho is to set the shift light trigger point.
The button on the speedo is to set and recall Vmax, 0-60 time, 1/4 mile, and / or set the lcd screen to read compass heading
odometer / trip, clock, elevation. I do not need 260mph but for the classic 'what will it do mister' it looks good.
In reality the reset button was right on the numbers we would optimistically run so the higher sweep of the clock face is to move the button out of the way. Having said that I am not sure I will be doing any speedo gazing at Vmax. They do a version with a clean face and a jack button with 18" cable out the rear - that would have been sensible but I did not know that at the time I ordered.