Oh my.
One question and one quite obvious suggestion.
How do you plan on balancing the russians, what with the outdated muskets they uses? And British units.
Infantry
(Can't think of a line regiment off the top of my head)
93rd Highlanders
Rifle Brigade
1st Foot Guards - I may be mistaken in believing they were decisive at Alma
Royal Marines, perhaps?
Light Cavalry
The goddamn Light Brigade!
Which, and I've probably missed someone, consisted of
11th (Prince Alberts Own) Hussars
13th Light Dragoons
17th Lancers
Heavy Cavalry
I don't know the heavy brigade all too well, but I know it included
2nd (North British) Dragoons - the Scots Greys
6th (Inniskilling Dragoons)
Some Headquarters ideas
Lord Raglan
Lord Lucan
Lord Cardigan (haw-haw) his uniform would be the same as the 11ths, mind.
General Scarlett, who lead the heavy brigade
Colin Campbell, who commanded the 93rd and later lead the British to the relief of Lucknow.
Lew Nolan, the impetuous ADC who said "there are your guns, my lord. There is your enemy!"
Just realised that the light Cavalry niggling at the back of my mind were the 8th (Royal Irish) Hussars. But damn their eyes, they weren't wearing damned saucy scarlet pantaloons, d'ye see?