I'm trying to figure out if I can finally move to the UK?

I have 300k USD will that cover the fees and minimum reserve to make the move to the UK my credit and everything is good in the states will that help me there? Also I'm a 3rd gen Irish-American & my family has an active homestead in Ireland still. I've heard that will help me get a dual citizenship in the UK as will marrying the man that I've been with for the last 6 years is any of this true and do I meet the requirements for extended stay?