If you are (for whatever reasons) after the highest gears you could i.e. combine the (aftermarket) S/A XRF8w with a factory 54t chainwheel on a Brompton and you'd end up with 11m of development / 139 gear inches (with the lowest gear being 3,4m / 43 gear inches). If this still is not enough you could go for a 60t chainwheel (roughly the max. that fits on the Brompton w/o modifications) or combine it with a Schlumpf HighSpeedDrive which would put you even further up. What kind of use do you have in mind? Speed-record on the Bonneville flats?

The Tikit uses 349 wheels as well and should therefor be pretty similar but can maybe handle even bigger chainwheels more easily (I don't know).