Money system + Inventory

I’ve tried this with SQL, but I’m not that advanced in it yet, so I will explain what I need.

I’m looking for a script that will give the player money for every zombie,fastzombie,headcrab,zombine he kills. I’m also looking for it to contain an inventory script that allows the players to purchase health kits, weapons, and ammo from the menu. Can you also throw in a HUD that displays the money.

P.S. I need the players to start with money.

I’m wiling to pay for the script depending on what you ask for it, I’d say it was a simple script(except for the HUD), or you could be generous xD