I have a 2015 xdrive35i and I want to get a camping trailer. What would you recommend for the max trailer weight? I know nothing about this sort of thing - my husband passed away this year and I still want to take my 8 year old camping (we live in Utah) so I am going to sell our 21 foot trailer and get something I can manage by myself. I was going to have the dealer install a hitch and am not sure if I need the brake installed too - I'm nervous ... any advice or help would be greatly appreciated! Thanks!