Need upgrade from 6.1.4 to 7.0.3

I am in need of someone to get my site from 6.1.4 to the 7.0.3 without loosing my database. We have almost 3000 members. The 6.1.4 has alot of mods but don't need the mods reinstalled. I will get new mods as I feel are needed once up and running in the 7.0.3 Also want done in a reasonable amount of time. Cant take two weeks to complete. And cant have site down for much more than a couple hours if needed.  I can do this myself having installed many mods, the new 7.0.3 on other sites so know the time involved. Just looking to get it done before I have the time to set aside to do it  myself.