Hall gives the following for the regiments you mention :-
- he quotes 3 references - all agree on grey coat with grey linings/cuffs - 1 reference states red waistcoat (from contemprary record of 1698) another grey. The third does not refer to waistcoats. Yellow buttons.
As a named province regiment, the drummers would have worn Royal Livery.
White/Lt Grey breeches.
(was St Laurent until 1691) - Hall shows 2 variants & pictures another. All show yellow metal buttons - no known details re musicians. White/Lt Grey breeches.
One agrees with the Grant listing of white/Lt grey coat & linings with red waistcoat - the reference for this variant is the work of Lienhart & Humbert c1900 that may well refer to later period c1720-30 uniforms.
The second refers to a blue coat with red linings that is from a 1692 reference (confusingly the Hall colour plate shows red coat lined blue but I feel this is likely an error). This uniform is likely for the earlier period as the regiment was initially raised by the Marquis de St Laurent from troops from various Savoy regiments & their uniforms usually had a dark blue coat. Perhaps the coats changed to the possibly cheaper Lt grey cloth after the Compte de Nice took over the ownership of the regiment (there were 3 Compte's de Nice sequentially owning the regiment - they were the 1st, 2nd & 3rd sons of the Marquis de St Laurent - so all in the family!)
- raised by Phillipe-Marie de Montroux from soldiers of various Piedmontese regiments after the Duke of Savoy changed allegiance. Hall shows red coat with blue facings & red breeches. White metal buttons.
As far as buying flags for these units goes, the dealers I know about are :-
Stuart at Maverick Miniatures does WSS Navarre & Montroux, Iain at Flags of War does WSS Navarre, and our own Warfare Miniatures does St Laurent/Nice (sheet FF007). All companies are excellent to deal with. There are likely some US suppliers also, but I am not aware of these.
Hope this helps & happy painting!