tuning machines for my vintage baritone

I recently picked up a 50's Harmony Baritone and want to replace the friction tuners with the geared upgrade. Is there any certain brand I should look for, and anything I should watch for. I'm not looking for anything as pricy as the stew-macs, but anything else I'm open to. I'm assuming I need to measure the headstock thickness...is there anything else I need to consider.

Thanks,
Wooville

Nice open back tuners that won't break the bank are Grovers. Stew Mac carry them if that's convent for you. Other places as well.

Besides the thickness of the headstock (they have short post and long post), you will need no less than 35mm between tuner holes and no less than 10mm from the edge of the head stock.