I saw a grab bar that looked like an upside down T, do you know of any manufacturer that has this available?

Yes, Jaclo offers a grab bar that is a vertical and horizontal bar in the combination of 24" and 32".  The item number is T-20-**H-**W.
  This item is available for special order in a variety of finishes, please contact us at 800.797.700 for pricing and availability.