If you only wanted to go to 4.7 litres you could use genuine Ferrari internals from the new Maserati Gran Turismo S, whos engine is basically a punched out and detuned version of Ferrari's 4.3 litre V8. I assume that the Maserati has a lower compression ratio also, which is what you need for forced induction conversions, otherwise the crankshaft will suffer some major punishment. If I'm correct, the only difference between the Ferrari version of the motor compared to Maserati version is the bore. I don't believe the stroke was increased. Therefor, you could theoretically just use the block/ sleeves and pistons from the Gran Turismo, although if the stroke was also increased in that motor, you may only get 4.5-4.6 litres with just the pistons and block/sleeves, but adding the crank could take you to the full 4.7 litres. These types of parts are actually cheaper than you would think even though they are Ferrari, compared to body panels, wheels, and interior bits anyway.
I cannot say whether all you would need for this is simply install new floating sleeves into the Ferrari block, or if the Maserati block is bored for larger sleeves. If the block is bored for larger sleeves, then I would suggest buying both the block and the sleeves instead of machining the block yourself, if just to avoid any overheating issues around the sleeves. The other things to consider with this setup is deck heighth, the Maserati pistons may be taller or shorter, depending on whether the cranshaft is the same or not as the F430 counterpart. This will affect your piston/valve relationship, and for all I know, the pistons may have different valve reliefs for this very reason.
Anyhow, that is just a suggestion, as I don't really have any blueprints to look at of either engine, so I can't be for sure how different those two engines are, and how many parts they do actually share with eachother, and the specs of the parts they do not share. All I know is they share the same castings for the heads and crankcase (block), have the same architectural layout, which includes cylinder layout, firing order/crank phasing, valvetrain layout, and oil system. All of the rest is beyond my scope of knowledge for this engine family.
Hope that helps some.