Good luck with everything.
I have been down that road. I tore mine and some other stuff about 6 years ago from a big wipeout while surfing in cape hatteras. I got the cadaver graft and was on crutches for about 3 weeks, but was healed up and running again in six months after P.T. After it initially happened I was able to walk on it and run after the swelling went down, but used a brace I was prescribed. During surgery however they discovered that the ACL was gone, and there was alot more that needed to be fixed (MRI wasn't showing a good picture I guess at first).
I would say talk to your docs and if you can go to surgeon that deals in sports medicine, they have the best advice on routes to take. If you don't have the surgery, have them prescribe you a custom knee brace that the insurance can cover (they are expensive). I surfed in a DonJoy Defiance brace with no problems and it is made for the ACL (alot of athletes wear them)and it will save the knee. Also, work it out alot swimming and building the muscles that support the knee. Once again good luck.