[El Sol Infinito]

Technically, no. However I have to ask: Why? How shot is your present interior? On one hand, there's so little difference between the two, I can't see the benefit. One the other hand, you're going to get smoked by Tbird enthusiasts for messing with it.
Here's what's different between the '64 and '65 that I can tell:
1. '65s offered power vent windows, hence 2 more power window switches and a different center console panel.
2. '65s had the convenience panel with two extra "bullet" switches in the center which controlled the newly offered power antenna and the map lights. The '64 had a more hidden map light switch on the surface of the convenience panel.
3. The '65s had a different AM/FM radio option with buttons that flip to switch bands. Doesn't matter if you have the AM only unit.
4. The door panels on the '65 incorporated a pull handle in the armrest (This is the most important improvement, I think) and used different courtesy light bezels (not as good looking as the '64, I'd say)

That's it as far as I know. I suppose the Landau had wood veneer trim and panel faces, but I think the wood stickers look like crud compared to nice clean brushed stainless...

The power accessories you talk about: Is that the convenience panel? If so, that's not really worth it. The vaccuum door locks are not needed in a 2-door, and the emergency flasher isn't needed (everybody's going to see you from a mile away, anyway). I say this b/c neither my flasher or my locks work at this point, though...
The power seat, however can be easily retrofit into the '64, '65, and '66, just swap out the manual mechanism for the power mechanism and hook up to some good power.
The two things I really had for my car: A power antenna, which would make putting on the car cover about 15 seconds quicker, and viable cruise control for all of the road trips I'll eventually take.
Good luck.