LED headlights, rear lights, front parl lights and interior for 1964 plymouth Valiant

Honestly the only headlights I would recommend are those that were examined for their technical performance by a non-interested person or team.
'Virgil' at Candlepower forums and Stern who posts in a number of forums are about the only people I am aware of who have access to that type of equipment or services, have actually used it to check bulb and beam pattern performance, and publicly discuss it.

of course I've bought my share of junk too - but eventually by paying attention to rally folks at the local SCCA meetings - I started doing things that actually worked (usualy).

Amongst the sealed beams I would look for older production in good condition, and then aim it properly!
If its not a points type restoration or similar, and driven at night, powering the lamps from the alternator using relays is the next recomendation.

But for new production, as Dan has already posted, the cheapest decently performing 7" round is the Hella "vision plus" with a good bulb.
For large rectangular lamps, he has some Bosch (or did) which in my subjective opinion I find as good or slightly better than the Cibies. Since no A-bodies came with those, seems pointless to discuss them further.

and if this point wasn't made enough yet.
Properly Aim the headlights!
This is a free performance upgrade.
A 1/4 turn on an adjuster screw can make noticible diffence.