Depending on the extent of trust you want, the ultimate (whilst being "reasonably" affordable) option is becoming a Nominet member.
Nominet are the registry for .uk. Anybody (person or business) can become a member and the core benefit of membership is you effectively become your own registrar. As long as you pay the membership fee, Nominet don't care.
You therefore cut out the middlemen.
Sure, Nominet could theoretically cut off your domain (e.g. if you don't pay your membership fees). But the bar is much, much higher than $Mega_Corp.
Unless you've got money to burn, probably a bit extravagant for only one domain name. But if you'll be needing a few it might be worth considering.
