Some questions regarding case fans and PCI slots

[Shizuki]

Hello.

I have a Corsair 500R

Newegg link with specs

I'd like to add more fans and replace the current ones.

I was thinking of 4 Cooler Master Sickeflow 120mm and 1 Cooler Master MegaFlow 200mm

I'm not sure if they would fit or not. How would I know? The case already has 120mm fans and the one 200mm. But does that mean all 120mm/200mm fans will fit regardless?

Also, I was wondering if a PCIe card would fit in a PCI slot? I have one PCI slot left and I have my eyes on this PCIe sound card
Creative Sound Blaster Audigy

The reason for this old card is because I'm not looking for anything high-end and I'm on a very tight budget.

Also looking to buy this headset and I was wondering if the above sound card will handle it or will it degrade its performance/quality somehow?
Logitech G430 Surround Sound Gaming Headset with Dolby 7.1 Technology

Would love your suggestions and ideas. thank you!

Mobo is ASRock Z77 Extreme4

 

[inzone]

Any fan that is 120mmx120mmx25mm will fit in the same place as the same size fan, same goes for 200mmx200mmx25mm or any other size fan with similar dimensions.

A PCI card will not fit in a Pci-e slot and a Pci-e card will not fit in a PCI slot.

The head phones are USB and as such will bypass the sound card since the head phones come with a built in sound card because of the USB connection.