I've never played them, but I too have thought Mr Bickley's rules look very solid. It probably wouldn't be all that hard to convert them to gridded action.
Another title you might want to check out, if only for inspiration, as well as some gorgeous eye candy, is Sands of the Sudan. It is a beautifully tarted-up edition of Peter Gilder's old Sudan rules that he used to use at the Holiday Wargames Centre, lo those many years ago. The player(s) take the role of the Imperial forces while the game mechanics control the Mahdist hordes.* They don't use a grid (though again, you could probably tweak it without much trouble), and tend to assume one has hundreds of figures, so be warned. The number of figures could definitely be scaled down without hurting the system. Anyway, just a thought.
* Gilder in turn based his rules on the classic Pony Wars set by Ian Beck.