Freestyle Motocross Help!?

Hey,I'm a 19 year old male and I'm looking to buy a 2 - stroke dirt bike for strictly freestyle. The Suzuki RM125 caught my eye but the only problem is that I'm only 5'5''tall and 160lbs. I feel if I get anything lower than a 2 -stroke 125 (like a RM85L) that I will look like a kid and not be able to perform on some of the ramps or do some tricks. Will not being able to touch the ground affect my ability to do freestyle? Is there any way to modify the dirt bike so that it fits me better? Another alternative that I thought of is buying an ATV but I would really like to buy a dirt bike. I would highly appreciate any suggestions.Thanks,Dan