Hi thezawesome1 here and I am providing you with something similar to garry's mod. It is a basic map and needs a few mods in order to play.

The mods needed are:

flans mod 1.6.4-
http://www.minecraftforum.net/topic/182918-164flans-mod-40-mechas-planes-vehicles-guns-multiplayer-tdm-conquest/

Gravity gun mod 1.6.4-
http://ichun.us/mods/gravity-gun/

I don't take credit for mods and both are not made by me :).

Another important thing will be the content packs which are found in the download, You can find how to install them on youtube!

I also don't take credit for the content packs!

You may also add more mods to further you'r enjoyment of Gmod inside minecraft!