Long time runner looking to TRI a new way to waste heart beats!

Start of by saying thanks to the genius who started this forum and site. So as you can tell from the subject of this thread I am a long time distance runner looking to get into triathlons. I have been racing with my legs for the last 10 years and started having back pain, numbness and pain down my right leg at the beginning of the year during a race. I had minimal invasive spine surgery for herniated/bugleing disk (L5-S1). Had a lot of scar tissue around my siatic nerve. Dr told me maybe I need to cut back on the distance. I am not ready to become a couch potato or herded into the Crossfit Farm. If you have insight on bikes/gear or startup training that would be awesome.

Oh yeah.. I am also 6'5 so I am having trouble finding a bike.
If anyone is local ( Fort Lauderdale FL)


Kevin