I am currently using a BC548 to drive
(which is bad)
bc548 max collector current is 100ma...
My datasheet says 500.
The simplest/cheapest thing to do would be to put in a 2n2222A which can handle 1A. Get one of the metal-can versions if possible - they dissipate heat slightly better.
yep, it says 500mA, but it also says "...as switches requiring up to 300mA"
the 2222A datasheet says 0.6A Ic continuous, and its VceSat @ Ic=500mA may be 2V !
If I had to chose a NPN transistor, I'd follow DC42 advice and go for a BC337 , only 0.7V VceSat @Ic=500mA .
Anyway, OP asked for a mosfet, I think he wants to give it a try, which I think is a good idea : always good to start with low values and simple designs
