I used Evan Williams Bottled-in-Bond (so cheap and so good, it's our house bourbon) and the Dolin vermouth simply because it comes in half bottles and I don't use a lot of vermouth. Someone else may be able to help if you want recommendations. I would recommend an assertive bourbon, though - with the other stuff it will be a little watery if you use a gentler one.

My go to bourbon for cocktails is the Elijah Craig Small Batch, mainly due to price. My sweet vermouth recommendation is the Death & Company house sweet vermouth, equal parts Dolin Rouge and Punt e Mes. I prefer that mix to something like Carpano Antica Formula Sweet Vermouth, but you can get that in a 375 ml bottle.