Much would depend on how big your wallet is, how you define WWII (flew during the time period, or truly saw combat) and how authentic you wanted to be. I would love to see more early jets, or look-alikes fly.
I vote a T-33 made to look like a P-80 would be an interesting project. P-80's were in the European theatre during WWII, but did not really see combat, but would be a good example of an early American Jet. Remove the constant diameter plug (24 inch I believe) which was put in for the second seat, re-attach the fuselage halves together, and fit a short single seat canopy. You could likely ignore the rear fuselage plug, a few other minor differences, and get pretty close to a P-80 clone. I believe a few folks have looked into this shortening and describe it as rather straightforward. Likely "easier" than any real P-80 project as not many P/F-80's survive-although the one at Yanks boneyard looks pretty complete. A good number of T-33's still survive (some flying), so good choices depending on your bank account, good knowledge, spares, etc... A T-33 with a P-80 canopy (without removing the mid fuselage plug) would look wonky.
Other ideas:
- Convince one of the Me-262 new build owners to part with their aircraft. Paul Allen is restoring a real one and has the resources to do so. Arguably THE jet of WWII.
- Meteor- a good choice to show a true WWII jet, but would likely be quite pricey to restore and operate. Most survivors are post war marks- which are "better", but do not represent those used in WWII. Not sure if the Martin Baker ejection seat test aircraft are planned to be retired any time soon. A small number of candidate projects.
- Vampires were flying by the end of the war, but it is not commonly considered a WWII aircraft by many. Production version did not fly until April 1945. Did not see combat in WWII. A good example of an early jet, but perhaps not truly WWII. Wooden components make for few project survivors that could readily become flyers, although a few flyers/close to flyers available.
- The P-59 project at Chino has been "almost complete" for years.
- Sponsor a new build replica of a type. VERY expensive for a real replica/new build built to WWII specs. Perhaps a look alike using modern materials could get you something that would look the part. I always thought a He-162 Volksjager clone using modern homebuilt type materials would be a neat project. Small and light, and with a small modern jet turbine in it. Sure it would only be a clone look alike, which purists and judges (and some WIX'ers

) might scoff at, but it would be an attention getter- and likely much more economical to build and operate than some other types. Reportedly handled well (unless the glue came apart)