Hmm........
Any end mill that fits your machine.....any end mill which are new or like new which you can buy cheap.....
Reground bought cheap....
Cobalt prefered, but HSS ok for your small machine, carbide when you can buy cheap....
2 flute, 4 flute, ball end, square end, center cutting, etc when you can buy cheap
What can i say......any end mill which fits your machine and you can buy cheaply,
RICH