Why would you care if the arms are moved? They are moved because its better for handling and increases the wheelbase. There is no negative to moving the arms forward. If you are that worried about it though, they have rear offset arms that will keep the wheels in the stock location, it says so right on the website if you'd look.
IMO, UPR is a good K for drag racing and street driving where handling is not the #1 concern. Yes the UPR K can handle ok but not as well as the MM setup will. Conversely, the MM setup is damn near as heavy as the stock stamped piece and still isn't optimal for handling itself either. That distinction goes to the $4k+ SLA (short long arm) setups from Agent47 and Griggs. The MM setup is also $1100 more than the UPR.
All that said, if I am a stick shift street car that wants to handle well, I am getting the MM front kit with the forward offset arms to move the wheels up 1.5" which centers them in the wheel wells incidentally. If I am more concerned about straight line racing its hard to beat the UPR and it is fine on the street. If open tracking and serious then probably A47 front and eat Ramen for 6 months.