No disrespect intended, but why not start with a bike with slightly more HP if that's what you are trying to get?
Building an entry level bike up for power, when your not racing it? I am not sure I get it. I GET modifying suspension for gobs of cash, but the motor?
There are bikes that come from the factory with 45 HP, up to 200. Suspension, of course is something that can be sorted at varying levels, depending on how much you want to invest.
The KTM RC390 is 45 HP, out of the box, leaving all that cash for Ohlins suspension upgrades....Now If I weren't born back when Moby Dick was a minnow, I might be riding one of them.
http://www.ktm.com/supersport/rc-390-2018/
and some nice bits to get you sorted for scaring tourists.
http://www.hardracing.com/15-16 Bikes/15 RC390.htm
Of course, the Best Investment I ever made to Any Bike was https://superbikeschool.com/
It made all my bikes a LOT faster. As it turns out that thing ON the seat is the most important thing to improve.
i have R3 and RC390-power is very similar.both have engine tuning,both have around 42 rwhp.both have shocks and fork kits.really fun bikes-ktm,little more torque,more vibes,easy to blow up,handles more like a racebike, and harder to ride,with short powerband,constant shifting.R3 easier to ride,easier to tune,more top end,bigger powerband,-the SV front end sounds awesome-solves brakes and suspension.i'm with chris-researching parts are a blast and the improvement you can get out of these cheaper,low tech bikes is pretty rewarding.agree about superbike school.

