I'm turning to the experts on the forum for some advice for brighter headlamps on my wife's E-type. Although we don't do much night driving, the lights don't seem that bright the few times we've been out after dark.

It would appear that halogen of some type would be the way to go, and is a relay suggested? If a relay is a good idea, is it difficult to install/wire in?

How about the ones by Barratt?; they don't mention a relay. Moss also sells them, but advises a relay. Moss also sells non halogen that they claim are brighter than stock.

Look forward to suggestions. Thanks in advance.

 

I used to restore vintage British vehicles for a living and I always upgraded the lights. To keep it stock in appearance but with a LOT more light is actually not difficult at all. The key has always been to also not draw huge amounts of electrical power.
Hella and many other companies make 7" round housings that take H4 replaceable bulbs. Then you can choose standard wattage or higher, and now even LED bulbs are available that draw very little. Absolutely you should use relays for hi/lo as it is always best to take the large draw out of the original harness and switch etc.
I've been using Susquehanna Motorsports for 20 years to source all my lighting gear. Great guys and great service/prices. They can guide you depending on which direction you want to go. They make a wiring kit that is plug and play with relays- you plug into the original wiring at the original headlamp plug, then connect battery and ground, then plug into the new H4 style bulbs in the conversion housings. Amazing difference. This can be done with stock appearing housings or the newer style that have clear glass instead of fluted lenses or even the old Lucas Tripod style replicas.
Cost with harness, housings, bulbs- maybe $200-ish. Worth every penny. I haven't tried LED headlights yet, but have a car that came with them from the factory and they are amazing.

 

I agree with VT Summit, many of vintage mustang guys have improved the headlights in our mid 60s and later mustangs through installing relays to separate the left from the right. It's quite common to replace our headlight switches due to the amp loading they pass. This burns them out prematurely. Relays take the burden off the switch and channel the amps to the bulbs. This alone will improve brighness. Also, splitting the Hi/Lo is a good option too. Jags with their cambric covered wiring is another a real danger point, especially, when it involves the AMP gauge.

 

I wouldn't do anything without first adding the upgrade harness with relays etc. That being said, to do so without installing modern technology halogen/HID/LED instead of the old sealed beams would be very little return on the investment/effort.
My Jag is running the susquehanna motorsports power harness with Sylvania 7" halogens. I'll probably be changing those to the E code Hella headlamp housings with PIAA bulbs. I ran that setup on my Defender and it was Hella bright and the E codes have a sharp cutoff- no complaints from oncoming drivers.