I wouldn't consider the mini round for hay too slow to make , and poor for stacking and of course the density / weight ratio , ideal for haylage though.
As for self powered balers, there are many, even a standard super hayliner baler with engine on top , belt drive to flywheel, very popular with the Amish farmers, the alpine farmers have lots of self powered stuff too, but its all abroad .
I rang the dealer about the Abbriata* small baler as its by forfar , its 3yr old and he wants more than the new price €8750 inc tax it sells for in Italy !!! ( transport from Italy non urgent groupage as long as its delivered by 04/20 is €400 ).
I will no doubt call again if its still for sale out of season.
* very low power requirement 20hp