It sounds like Jake is doing extremely well. The tail wag and ability to urinate on his own along bode well!
We have fit quite a number of Basset Hounds over the years. You can see a story about a rescue basset "Benjamin" that we helped at: K-9 Cart Company East Blog. Look around the website for more information, pictures, and videos, too.
Most vets would recommend waiting a few weeks after a laminectomy. We can build a custom dog cart/wheelchair in 24-48 hours after we receive the measurements. So the hardest part now would be to measure "Jake." As long as he has good forelimb strength and is no longer in any pain, you will probably be surprised how he immediately would take to a cart.
Please give us a call if you want more personalized advice or information.