remember that the Reitars have turn backs, while most ECW cavalry would have had buff coats see: http://www.metmuseum.org/toah/images/h2/h2_15.113.1-5,29.158.885.jpg
So, if you make some buff coat out of model putty, and put some helmets on the bodies, you will have some ECW looking cavalry. (apart form the horse furniture and carbine's points Bill mentioned)

Thanks for the advice chaps, looks like a conversion is possible with a bit of work, should be fun! BTW, does anybody know of any ECW uniform websites?

Thanks again

take a look at this web site for the biggest and oldest re-enactment society in the U.K, should give you all the leads you want

http://www.thesealedknot.org.uk/index.asp

cheers old john