Hey Chris N Jax,
The biggest problem with the 17 is that the hull volumes aren't really made for two people. Depending upon your total weight (I won't dare ask a woman
), if might be sluggish with two people on board. When racing, the 17 is made to race solo, but not the sport version. The official class if for the normal version, without a jib.
If you raced 16s before, why don't you look for another? Their kind of like "Texas Hold 'em"...Easy to Learn, A lifetime to Master. Your familiarity with them would probably help build her confidence on the boat more quickly. They sail with two better than the 17s do (although I really like wings). They are also generally available used for really good prices. I don't know what area you are in, but you will also find good racing still on 16s and maybe could get your girlfriend to crew with you.
Just my 2 cents. Good luck!