More time posting than coding
I did similar. Moved 2 pensions from 2 different providers from previous permie work and start making monthly contributions from my ltd company. At the time from my research the best in terms of costs seemed to be HL, end up going with AJ Bell as for self managed investments was about the same as HL and the account opening process seemed much easier!
Check if fidelity charges anything for transfers first, AVIVA and Legal & General didn't charge me a thing. Even if they charge you, check how much you save yearly in fees as most of the time any transfer costs can be surpass for the savings on yearly fees pretty quick!
"The boy who cried Sheep"