Good quality roller rockers are expensive. Yella Terra make about 3 or 4 types for Ford V8s if you want a domestic product.
It depends on your springs and cam profile as to which way you go.
I think you are looking at 600-1000 dollars for a set worth trusting personally.
I just pulled my crane hi bleeds out of my bbf. One failed. I replaced them with a set of standard crane hyd's.
I used exactly the same technique for installing as far as preload.
As far as your lifter settings and preload goes. Any street or non race engine should have 20thou to 60thou preload, regardless of lifter if a hydraulic flat tappet style camshaft is used. If you use less you will have excessive operating motion in the lifter and increased wear.
Please reread the PDF files on Cranes site before using 2 thou.