stock internals will dyno out to 356hp for at least 1 pass. the stock fuel system will support that HP on C16 with a 50/50 injector split.
Realistically you will want the following:
Wossner Pistons
Wossner Rods
APE Studs
Gen 1 valves or other stainless valves & matching springs/locks/retainers
For 300hp or less i would not do oiling mods. however you know good and damn well you'll get bored and want to push it harder and farther. build it once or build it over. twice. like i had to. DOH!
Wildphil (dan) is my primary builder/assembler. We prepped my 2011 with all wossner internals, 1/2" studs, cometic gasket. Cases prepped by bill pippert. all oiling mods done and oil cooler bypass installed. sent the head to APE for Gen 1 valves & new springs/retainers/locks. it is unported and on stock cams. Turbo Kit by Buck @ NTR with Turbonetics journal bearing GT28 class turbo and billet non-intercooled plenum. Fuel system is a Bosch 044 with a 1:1 regulator, all -6an everything, billet rail from RCC with 62lb secondaries. Bike tuned by Schnitz on E85 makes 460whp @ 24psi. 264hp on 6psi 93oct.
This combo cost breaks down as follows:
Turbo kit was custom fabricated as a one-off kit and with the billet plenum (also a one-off piece) was a tad over 5k
pistons and rods were 1200
studs were a couple hundred
APE headword was ... I want to say 600 bucks
fuel system was about a grand
Tuning at schnitz was 6-700 (multiple tunes for E85 and pump 93)
Log Box setup was 349?
We recently added a AMS-2000 for 2180.xx but we first had ECU boost control. that was under 100 bucks.
We added a NLR Boost Comp Lockup as well after we smoked a stock clutch pack at 460hp with 6 Gen 1 SHD springs. We have since stepped back to stock springs and the clutch is on it's 2nd season. if you street ride at all the boost comp is the way to go. it was 800 bucks from RCC/NLR.
You'll have 10k wrapped up in it EASILY by the time you get all the little things you'll forget about if you decide to go big instead of going home.
Even if you try to get by with just a bolt-on stage 1 kit...you'll probably have 7k wrapped up in everything...might as well drop the extra 3g's at that point...