i think, that you need a COA to marry in the UK, and then apply for a spouse visa in-country - no need to go back home. The spouse visa will cancel your work permit, but on a spouse visa you can work with any employer you like - i.e. no need to ask the HO for a new work permit every time you change employment.
the spouse visa will last for 2years which will allow you to apply for ILR, but as you've been in the uk a year, you can apply for naturalization as the spouse of a British citizen immediately after obtaining ILR.
