Full Tutorial (with possibly all equipment/weapons):
I haven't checked to see if it works, but as Decency said in his post simply make a buy script. What this does is allow you to bind keys to buying weapons.
Find default.cfg in Steam\steamapps\common\Counter-Strike Global Offensive\csgo\cfg and open it in your text editor.
Next add in the script with the things you'd want to buy to the bottom of the existing script. Taking the script pointed out above, you could say:
//Print to console
echo "Press F1 for AK-47 / M4A1"
//Set items you want to buy, seperated by semicolon
//alias sets the following word to a variable to be later used
alias "buy_ak-m4" "buy ak47; buy m4a1"
//Then you bind it to a key using the alias!
bind "F1" "buy_ak-m4"
What I also noticed is that there is an autobuy.txt script already in csgo, under folder Steam\steamapps\common\Counter-Strike Global Offensive\csgo. You can type autobuy into the console, or press F3, and it will work. You could try modifying that script to fit your needs.
autobuy.txt also contains a list of most weapon aliases you can use in the buy-binding script.