You're going to need to locate ordinary barley, probably organic because a lot of grains, pulses, dried goods in general are irradiated to prevent germination, a problem I have encountered sprouting my own grains. I would suggest you look for organic barley grains also called organic barley berries and if that fails you'll need to look at the sprouting your own market. I'm pretty certain you'll find it, but I did question how you think after sprouting your own barley, you think you'll proceed from there.
Malting barley requires 3 steps. 1 is soaking the barley grains/berries in water usually at a lukewarm temperature, 2 is germination the drained grains/berries which requires regular turning and heat throughout & 3 is drying the grains/berries at a specific point in the germination process. You'll then need to grind the dried grain because otherwise you'll have whole berries still...
As for wholegrain farina, it is possible to purchase it although given that farina is ground/milled wheat minus the endosperm and you're wanting that, isn't that just wholegrain wheat flour? I honestly can't get my head around that one, so I'm probably wrong on that assumption...
As for mixing them together, I guess you are referring to quantities? Never having come across the product before, I genuinely can't guess as to the ratio, so I'd suggest that you start with just working out if you even want to be germination your own barley to dry to them maker your own flour from in the first place.
