Your pred looks really good nick. Atmo my ESC is mounted, like yours, above the servo. The whole thing is not sat on the servo, I have mounted it so that it hangs slightly over the propshaft but still doesn't touch it. I am, however, looking into converting the car to use a stood up low profile servo which, asyou can see, is a lot neater way of wiring up the car.
As regards to spares - I don't know what you have ordered but the only parts I have broken are rod ends [on the end of a wishbone or pushrod], one front upright and a spur or two. So those are what I would recommend getting although it may be useful to also have one of each wishbone, a pair of wing mounts and a diff gear.. just incase.
Upgrades - I suggest getting the x10 rocker pivots or wait and get the new ones, which will be similar, coming out soon. Also the shocks, which you already have, and the Lunsford turnbuckles [which you can buy a set off me if you want
]
Paint - I would recommend Telboy from telsshells [who did both my bodyshells and my brothers] but he has gone on a break now due to new members of the family I believe. So because of that I would suggest Blitzboy or Jon Miller. If you look at both the Blitzboy thread and the Jonmiller thread in the R/C graphy section you can get a taster of what each of them are capable of. You will also lots of posts by them so you can PM them on here for prices and other details etc.
One-way Prop - I have been running this recently and would say it is an improvement to the car. It is drrivers preference though.
hope I have helped
pm me if you need any help with the car, or ofcourse post on here
Matt