The weak point of the RC51 is the stock cams.
They're cast and have been known to break in half if welded and re-ground with higher lift and duration profiles.
For performance cams, insist on billet cams, preferably with adjustable cams gears to dial in perfectly.
And if you're going for performance cams, use performance springs and lighter retainers in the valve train.
And since the higher lift and longer duration cams will lower your effective compression ratio at lower RPMs, you may consider higher compression pistons.
JE pistons are advertised as 12.8:1, but have an effective compression ratio of around 11.5:1 with performance cams. That combination can live on 93 octane pump gas.
So for pistons, look at JE or Wiseco.
For cams, you can inquire at Kent Cams Ltd in the UK.
For titanium retainers and performance springs, try Kibblewhite Precision Machining, Inc. in Pacifica, CA.
For stroker cranks, you might check out Falicon.
However, since a stroker crank is going to put your deck height totally out to lunch, you'll need shorter rods or pistons with offset holes.
So that would mean Carrillo titanium rods.
Or, you could learn to love the RC51 as it is and take all that money and place a down payment on a Ducati 1198S with 170 HP or KTM RC8R with 180 HP.
As Clint Eastwood (as Dirty Harry) said, "a man's got to know his limitations".