I've been debating on and off for several days now between possible troop purchases.
1) An artillery battery, which would give me some firepower of note alongside my infantry battalion.
2) A group of Hussars in Busby. I'm seriously considering doing all of Hesse-Engelburg's Hussars in busbies. In particular, I'm pondering doing the Fuchshöhle Hussars with a particular coloration in mind. Whether I can pull it off is another question. :>
3) A second battalion of Musketeers. If I follow this option, then I'm probably going to ask for a custom bag, replacing a few of the officers and musketeers with officers with spontoons to fit out my desired count of 1 per company.
Any number of a thousand other combinations are in my brain of course ;) One of the other interesting possibilities is doing a unit of Jagers using the hunting shirt figures from the French and Indian Wars or AWI lines.