MW2 Prestigue question

If you prestigue in MW2 do you have to restart on all of your challenges. Say that you are 1 Mile from getting Marathon Pro but you prestigue, would you have to restart and get all the way up their again or can you just get that 1 mile to get it in prestigue. And if you are 1 of Interference III can you get that 1 counter UAV to get the Emblem or do you have to restart. And do your killstreak rewards reset and do you get to keep your Gun unlocks or does it reset.

you loose your guns, pros and challenges. you keep your emblems, titles, leaderboard stuffPatChampsXXXVI

you lose all the weapons, attachments perks custom classes and kill streaks. all the challenges are reset, the only thing you get to keep are the tittles, emblems and of course leader board stuff. after you prestege you unlock new prestige related challenges and can only get certain emblems and tittles after you prestige. an example would be "silent vet." tittle you must prest. atleast once and then get 50 kills with a silencer.