OK for those that ride here is the question or suggestion. I am 5'4" and have a long torso with short legs so what would be the best bike to buy. I have my heart set on the ninja however, I am open to suggestions.
A Ninja 500 should fit you. The 600 and 650 have taller seat heights but are both better machines. The 500 and 650 are both marketed to newer riders.
Not sure what other sportbikes have a seat height close to what you need. I have a Yamaha YZF600R and at 6'2" I wouldn't mind having a taller bike (I feel like that on MOST sportbikes though).
If you're willing to put a little work/money into a bike you can lower almost all of them. Sit on a Ninja 500 and see how it feels, check the seat height, then compare it to some other bikes you like and see if the parts are available to lower them to a suitable height. Custom seats are also available for a lot of bikes with less foam (or more) to adjust seat height. Just a thought.