*Mods, feel free to delete this thread in General Tech as I just noticed this sub-forum is better suited and more viewed

Anyways,

I picked up an 02' Towncar recently, and my goals are to build a very comfortable sleeper. I'm not looking to win any drag races or dyno competitions, so keep that in mind.

Up to this point, I've installed a brand new transmission, 4.10 rear, stripped the air ride and replaced with shocks (TONS of body roll with the air ride, as Im sure you all know), new performance tires, and Magnaflow true-dual exhaust (quiet but has a slight growl and rated to about ~300hp).
The car looks 100% stock and isnt loud which is exactly what I am going for.

From here, Im satisfied with the drivetrain and am ready to begin on the motor. It's of course the 281 4.6L (hence why Im here) and am apprehensive to begin ordering parts before knowing what will suit what Im going for. I'm currently thinking heads, cams, and intake, as well as other small bolt ons such as pulleys, etc. I would like to keep the stock bore as I do not want forced induction to be ruled out in the future (though Im sure Ill keep it all motor indefinitely).

What Im looking for here is suggestions as to what exact models of individual parts at a reasonable price that will allow me to net the highest gains. A smooth idle is one of my biggest concerns, though I can live with it being a bit more aggressive if its pertinent to higher gains.

In closing, Im not shooting for any particular numbers and I appreciate your reading and replying to this thread. If pictures are of any interest, I'd be happy to post some. Thanks!