This is the best motorcycle smart phone application I have found.
Have you seen this? http://cycle-ergo.com
You can put in your height and leg length, and then see how you'd fit on different bikes. (I'm short-ish, so have the opposite problem from you).
I did my CBT and have now got a 125, while I take lessons on a bigger bike to take my full A licence. I feel like I've gained a lot from being able to practice/ride between lessons.
MCN Fantasy Road Race 2015 - in association with Bennetts.co.uk
Come on then, don't be shy.....