Well, unfortunately you have to have high stat horses to have a chance at getting offspring with such stats. ArtemisV sells fast horses at very reasonable prices on smp1. I sell high stat horses at higher prices on smp5, if he is out of stock. But really it just takes time, patience and a whole lot of gold carrots....but breeding high stat horses from low stat horses is very very hard. So get some better breeding stock and go from there.
Ok, I will breed every now and again. Good thing I know where a gold farm is! I also have a carrot farm.