I got an Uncaged Ergonomics Rise Up electric standing desk about 2 years ago. You can order it direct or through other resellers. The tops they sell are supposed to be really nice, but they add a bit to the cost. I ordered the frame only online from Bed Bath and Beyond because I had a 15% or 20% coupon (I think it ended up being $250). I'm in Amish country, so I had a 5/4" pine top made for $60 and added a plexiglass sheet. You can get tops at Home Depot or Lowes too (butcher block, melamine, etc.).
It is really built well. Tech support is available by phone or email. I only needed it when the controller had to be reset. I think my only complaint is that it doesn't have any built-in wire management, but that's easy to work around.
Some specs:
- 2 motors
- 4-custom-preset controller with display
- Height from 26" to 51.6"
- Adjustable width 42.3" up to 71" - the top can probably go another 12" (6" overhang on either side)
- Handles up to 250 lbs.
- 5 yr. warranty.
https://uncagedergonomics.com/rise-up-electric-adjustable-height-standing-desk/