Busing is provided to the "assigned" school for a particular address in Hillsborough County.
Also many of the Magnet schools will provide transportation. If your children are able you may want to consider the International Baccaulearate magnet elementary, middle and high schools. The High Schools provide possibly a better education than the best Private and Parochial High Schools in Tampa Bay yet they are free and transportation is also provided. In High School it is very competitive to gain admission so an IB Middle School may help to prepare your children.
Hope this helps.
Oh and if you have a responsible credit history but just need help with downpayment and closing costs, you may be able to get State of Florida bond money to help you buy a home while prices are affordable.
All the best,