Hardware Upgrade? FSX? P3D?

Hi folks! Must be winter, I'm back on the forum!

My current {a relative term indeed!} set-up is a Dell 9150 I rescued years ago (2-core 8600 3.0 Mhz/800 Mhz fsb/4G ram/160G drive/ATI 4850/2 ea. 23" monitors/XPPro/FSX-Accel) and re-purposed for simming.

My very specific sim usage is a Carenado 182RG, the virtual panel of which I set up to match a specific full-size airplane (530/a\p/HSI/, etc). Have all the scenery/object sliders set to minimum, as all I need is enough detail to complete a take-off/landing (most time in clouds). It is used for IFR re-currency training (non-loggable of course).

XP having lost support, I have purchased Win7, installed, updated, and then authenticated on another h/d in the same machine (then ghosted so I can have as many fresh ones as I want for this box :-) Win7 performance tests say the cpu is the limiting factor (4.7) with the other components slightly above that (up to 5.5 I think).

My major question is FSX again, or P3D 1.4?...and/or corollary...continue with this computer or bite the bullet and upgrade (then including P3D v2)? It would be nice to load faster and bump the sliders up some. Heck, I might even play with other stuff on it...it's a long winter.

Ancilliary questions....

Will P3D 1.4 be a significant performance gain over FSX (thinking 64-bit/multi-core support) on the current setup?

Will my panel mods be transportable (via the panel.cfg file) into P3D?

What would be a reasonable computer upgrade for my purposes (which are certainly not whiz-bang top-of-the-line like most of you amazing folks are doing).

Thanks in advance for your suggestions and dialogue!!

Jim