At some point i want to change/swap out some lamps on after market lights. My question is what type of lamps should we use?
The fitting is Ba15s.
I`ve had look on the .net and and Canbus comes up quite a lot.

Change the whole unit. I tried the bulb replacement led and it does not even come close to LED Headlamps.

Ditto, change the whole unit. It's a great upgrade (brightness, lower draw).

You can ignore the CAN bus warnings. Morgan does not have a CAN bus, so the problems that arise in cars that have CAN bus system that sense the bulb current don’t arise.

Agree with others, replacing the whole unit is simplest. The expensive JW Speaker headlights recommended multiple time in prior threads work great. I fitted them recently.

Won't be relevant to Americans, but to Brits who may want to drive in the Eurozone, how do the LED full headlamp units adapt to RHD? Does one use a sticky bit of plastic tape as per the Halogen headlamps? I would have expected some LED lamps to be switchable but not seen that offered...

BA15s is a common single filament bulb fitting and not used on an M3W as they have OE LED's other than headlamp fittings

Car Builder Solutions have replacements for the OE LED units used as stop/tail, fog and indicators. Would recommend full dedicated LED headlamp replacement though with DRL function.

As suggested no Canbus issues with M3W and most of the trads.

But it is not the headlamps you want to change, is it? If the socket is Ba15s, it sounds like DRL, rear DRL, indicators, stopping light or the like. If you have a car with canbus system and ordinary incandescent bulbs, the system migth give you a bulb failure warning when you put in a LED, unless the LED is built to be canbus compatible. If the car does not have such a system, just put in a LED with the same socket. I have no idea about the M3W.
If you put a LED in the indicator lamp, it might go into "hyperflash" - a very quick cadence unless the LED is specified as non-hyperflash. A few are, most are not, but you can put i an extra ballast/resistor.
Remember, a red LED behind red lens, a white LED and red lens will turn out pink.
Concerning headlamps, there are LED versions of most bulbs, H7, H4 and others. They are a direct replacement, but possibly not road legal in the UK - you'll find out. Watch the canbus issue, though. I do not have personal experience of M3W headlamps, but they will most likely be a lot better than OE. It might be even better though, changing the whole unit. So the question is how bright is bright enough for yor kind of driving, how much are you willing to spend and how invasive do you want to be.

Apart from the headlights, all the light bulbs in the three-wheeler are LED from the factory (in mine at least), so I assume this is in fact a headlight question.

Rockabilly John - are you asking about the marker/side-light bulbs in the European headlamps? (The US ones don't have these)

Right, and I now understand that all bulbs exept headlamps are LED. But the headlamps cannot be BA15s? I am confused, and I seem not to be the only one. Perhaps the thread starter could specify the problem a little more?

High Robbie, yes ,thanks for the reply.
I have a set of billet ally lights that i bought to replace the cheap plastic front indicators.
These lights are fitted with typical lamps for this function.

I was just unsure if replacing led lamps with incandescent lamps would cause a problem, thats why i want change them for led`s.