siewcu

For starters - it won't be cheap, if you want decent quality PTZ cameras. Also NVR/DVR will be better choice than PC as a recorder(software ain't cheap). Or you can buy something on aliexpress and pray that this'll work when you need it.
 
IMHO - I've recently seen something like Dahua TiOC camera and I'll go for it, then NVR(with built-in PoE switch, or external PoE switch - if you want to power it that way) with WizSense - and you'll have decent quality without spending ton of money. And forget about PTZ, around house it's pointless. Cheaper option is to use analog hardware, it isn't as bad as a lot of people says. Except situations where 8Mpix isn't enough... Your choice. I've built CCTV for small place(like around a house) with Dahua analog CCTV - 3 8Mpix(HAC-HFW2802E-A-0280B, it's discontinued but has good 1/1.8" CMOS sensor) cameras outside, 3 5Mpix(HAC-HDW1500TLMQ-A-0280B-S2) cameras inside, WizSense XVR(HDCVI 6.0 Plus - XVR7208A-4K-I2). Price is reasonable, SMD+ will do its work when needed, and maybe even alarm out... And I'll suggest something like this. Good thing is that you can go up to 4K using UTP cable - passive video converter like PFM800-4K plus DC connector and you can have one UTP cable to power a camera and send image through it.

Yep. Change your case. I've had this one, airflow is really poor, also cable management is extremely hard - custome one is only way to have it working well. TBH only advantage of this case is 5.25" bay... To keep it cool it'll be loud. Lack of fans and airflow is extremely poor.