Wow, Thanks very much for all the answer. When I sayed that I think it's stupid to install all the port tree just to search, I meant that the ports tree is for install object from source. So if you just use it for searching, you're not using it for the right thing ? But thanks for the pkg_mgr and pkg_info -Q, I didn't know about them. I asked if there was a bootloader because I would like to dual-boot with Windows 7.
But thanks anyway, you respond too all my answer, you're all very great ! :)