Ah yes, the Do I build it NOW ... or wait? decision. Never an easy one. I faced the same thing when building an updated USS Enterprise for a friend, they needed it by Thanksgiving, so I ended up spending quite a bit on white custom decals and some other things. Of course, six month slater, Gold Medal Models came out with their supercarrier decal set!
As to Tom's, his sets are always at least adequate to good, and every PE set is going to have some different things in it. It's your decision on how long you want to sit on that monster before you try to hatch it.