I don't think anyone makes any rifles for that round. If I understand correctly, it's based on a necked down .223 so it seems like a .223 rifle will be easy to convert. I have no idea how easy it is to find brass and dies for reloading either.
If the .17HMR is not hot enough, Hornady recently released a .17 Hornet based on the .22 Hornet. Also, Winchester just launched a .17 Super Mag. It's a rimfire but it is hotter than the .17 HMR.