I need your help

Hello I need help or advice

I had a imac 24 ", but I missed playing in the PC, was installed via bootrom win7, and as always had the imac booted into win7 therefore decided to sell the iMac and install something more powerful to play ...
Now I miss the mac applications, hahahaha so plan to sell my PC had newly set to buy back an imac ..

After the introduction to say that someone told me that I could install leopard on my pc and so they can keep playing on the PC and Mac applications also use both like me

But I'm rookie on these issues

I5 Intel 750@4.0
Asus Maximus Formula III SB X-Fi
Thermax Spire Cooler Eclipse V2 + Enermax Magma
Rippler Exceleram DDR3 1600 4GB 2x2GB PC3-12800 CL7
OCZ SSD Vertex 1 2 120 GB
1 HD 40 GB (for security copies)
1 HD Western Digital Caviar Black 650 GB
CoolerMaster CM-690 Cooler II Advanced + 8 "Coolermaster
Enermax modular 87 + 700W
Asus Nvidia GTX 480
HP ZR24w IPS
Wifi network card TP-LINK TL-WN851N
Sharkoon Card Reader

I can install leopard on this computer?
What version, how ...?

Do I have to repartition the SSD (now win7) with what would have to reformat and reinstall win7?

dual boot? Or better to install leopard and then install win7 on another partition via bootcamp?

Forgive all the questions that you do

Sorry for my bad english

Regards