I produce hex based battle games though some blow up my game maps and do miniatures with the game counter behind as there is only 1 unit per hex. I have been working on a game on the Battle of Vinegar Hill and doing all the research on units and uniforms and created a design Facebook page where interested folks could follow the game development process:  https://www.facebook.com/profile.php?id=61564653026253. I am going to give a miniature version a go.  I thought I would share my thoughts on proxies, not an exclusive list but hopefully of interest to some:

Crown (British)

Line infantry NPR 21

Light Infantry AWL3

Dragoons NPR27

Fencible Cavalry NBR5

5/60th Infantry NBR3

Fencible Infantry AWB5

Hompesch Mtd Rifles (did a head swap with NBR3 and SBR4)

Artillery NPR 28H

General NSP12

United Irish

Pike NSP3 (remove muskets and add .08mm styrene for pikes and can mix some SKW3 for the regular pike but more regularity for experienced pike)

Muskets NSP4

To add some variety for above and for artillery, NSP 17

Generals NSP 18 and NSP 12- did a little carving hats off and adding brimmed hats from other packs for priests)

Women WEC 13

Cart Artillery- cut off wheels and trail and put on pared down equipment cart)

Many thanks for sharing.  I have had a couple of queries on the subject over the years, so it's great to have a resource to refer to in future!

Oops, militia infantry same as line: NPR 21.