You can use BT30 toolholders for the F1 & PCmill 50 & 55 series. As mentioned above the collets are ER25 style and will also work. You can buy pullstuds on ebay from a company in Canada "dandmfg", I have purchased both the pull studs and the EMCO style holders and they are fine. They copied the EMCO holder and offer them hardened steel.
I am getting my own PCmill 50 this Thursday, cant wait!!