You could opt for a Greenspeed tandem and the IHPVA will let you race in almost any of their events!
And then you can take the whole family for a nice Sunday ride on the same tandem!
Greenspeed; makers of fine recumbent tricycles - greenspeed.com.au
IHPVA; International Human Powered Vehicle Assn. - ihpva.org
Sunday ride; My 12 yr old stoker, my 6 yr old "cargo" (he has a seat on the rack w/footpegs) & the 3 yr old twins in the Burley trailer.
Pricey? Dollar wise; maybe. Cheaper than some, more expensive than others.
Worth it? Worth every penny!!!!!!!!!!!!