The 300m and 300 m spacing is done by rolex purposely so it doesn't mean if there us a gap or not it is a fake. They are both made that way by Rolex on different year models themselves. This will not indicate a "fake" Rolex.
The V7 currently on offer is as close as money can buy. If you want closer, interns on material then the v8 is using the 940L steel which is the same steel as used on a gen.
The movement on these come with ETA's on the V7 and 3135 on the V8. The V7 also accommodates the 3135 movement which is dressed as the gen moment but is known to be unreliable as with the V8 but too early to tell right now since no one has acquired one and reviewed it.
The difference in buying a 3135 will give you better crown height to gen an obviously will look similar when case is opened. The biggest problem is the reliability of the 3135 movement itself.
Most people stick to the v7 and mod the insert, crystal , etc. If you want to dress it to the 9's you can try to get a v6 which has correct CG's and turn it into a Franken by using gen parts but this will cost thousands of Dollars along with a good watchsmith.
It depends on how much you want to spend and how much time you have.
Most will suffice for a V7 with an ETA movement for reliability and mod it even thought it also has its flaws like Cg's, insert colour, wrong crown height.
If on the other hand you do want to spend large amounts to make it a suer rep, be informed that you will need a V6, V7 or V8 housed in the 3135 movement as the gen dials, hands, Datewheel, and gen movement will not fit the ETA counterpart.