You can open a motorcycle from 249ccm to over 250ccm

Hello together, maybe someone can help me. I need a 250er with at least 20Kw/27 Ps and max 25Kw/34 Ps but over 250ccm. With ABS. The new Honda 250cbr model 2011 would be something. But it has only 249ccm and 26,xx Ps. Can you make a displacement increase or performance increase with TÜV. I need a really small machine for my driving school that doesn’t weigh much. Although I have a 650GS that is extremely low and weighs only 200KG, but still need a smaller, deeper, lighter machine, for my little girls with ABS.