Note you are in staffordshire- high risk tb area so presume testing annually? If so, bringing a bull in on hire could be difficult. You might be better finding someone to AI them. Keep in mind you'll also need adequate handling facilities for tb testing every year. It might be worth you going to see a smallholder with a similar setup to what you're planning, cattle are a different kettle of fish to sheep in terms of handling and care and take a lot longer to become beef so whilst you may have 2 cows in the first year, by year 2 you should have 2 cows and 2 calves, then year 3 2 cows, 2 bullocks and 2 more calves and it wouldn't be until end of year 3/year 4 that you start to send some off for killing.