this is where a bit of foward planning will come in handy, allot of clubs and tracks dont allow clones (yes i know sounds very unfair) so if you think this is something you might want to race (even a slight maybe) i would go genuine HPI (or now even Losi).
ive been into largescale rc for 2 years, owned a HPI Baja 5bSS (for a week, didnt like it so it went) and a number of FG's so trust me when I say regardless of which they are both going to need upgrades to be reliable if you bash even half hard.
if budget isnt an issue you might as well go genuine, that way if you want to join a club you will have no restrictions. At the end of the day however whats the point of buying the model @ $1500+ and spending on upgrades when you can spend half that and buy the upgrades your most likley going to end up buying anyway?