Two in front...or two in back

[Fuzzy]

I've not ridden either but my vote would go for whichever had such a geometry set up that it would still lean into corners, so probably 2 up front I would guess?

If wanting to lean on three wheels you need something like the Piaggio MP3. Front wheels close together and independent suspension. Not for handicapped as they are heavy and do fall over. They are a lot of fun and there are rumors Honda is playing with an NC700 version.