Welcome! Sky's the limit lol. Ironically I'm finally getting around to finishing parting out my modified 06 R/T (medical issues are a PITA)
Tuner - always good, I have an unlocked DSP U7135 if you're interested
TB - Find a used one, or save your money. Not really any return on investment there. 5.7 uses the same TB as 6.1; this will be handier once you start going through internals and/or forced induction
Intake manifold - this is where your old car is showing lol. Can't do intake swaps nowadays like you could on old cars. There is no direct bolt on intake for that engine; to put an eagle intake on you'd need the manifold, spacer adapters (to mate the ports and clear the block up front), the adapter fuel line and swap injectors, unless you have enough cam (which you didn't list) to need the eagle 5.7/6.1 injectors. With a stock cam there isn't any point to swapping that intake.
Full exhaust - also always a good idea. Have a Magnaflow catback if you're interested.
Don't forget the rest of the car. Stock 06 R/T's don't handle for shit & that 2.82 ratio is great for mileage but not the hot ticket for any kind of acceleration lol. A cheap easy upgrade suspension wise are OEM police sway bars and 05-10 SRT take off struts/shocks/springs. Did this with mine with the fattest tires I could shove under it, which a the time were 245's on the stock 18x7.5's. Initially upgraded the rear brakes to the cop version (same caliper, bigger rotor, different pads). Eventually a Brembo swap, SRT wheels, a 3.06 Getrag, MTCM, etc etc etc found their way in. Even my prized Grant steering wheel (which may be on the market soon). I still have a bunch of stuff, lemme know if you're interested.
When I got it:
After most mods:
And what the locals did to her:
Enjoy modding your car, almost guaranteed with your whatever you want to do to it, it's either been done or figured out why it can't be.