Any advice on joining the Household Cavalry as an officer?

I'm thinking about joining the household cavalry as an officer but I'm not to sure I'd get in as most applicants have to be part of a well known family or have a good background, I come from an alright family but I think I might have to change my name to my grandparents' as my name 'Wiper' isnt to appealing however my grandparents is alot more posh and I think I would have a better chance of joining if I were affiliated with them. I know I'm mentally and physically ready and would have a better chance of joining as an artillery officer or something like that but with the household guards being closer to where I live I feel like I should join.