Monitor

Hey guys, I was wondering if you guys could help me out, so I've got like 3 DVI ports in my PC, one of them being DVI-D and I believe the 2 others are just DVI. I don't know how many monitors I can run. Also, do you think I could switch the thing out where all the USB ports are, and the DVI ports, and so on so I also can have HDMI/VGA ports? I'd really like to just switch it out, incase I can't run 3 monitors. My computer case is a Fractal Design Node 304 and I can provide pictures of the back of my PC if you'd like.
So my questions:
Can I get that thing in the back of my PC switched out so it can support HDMI/DVI/VGA and so on?
How many monitors can I currently run with this PC? 2 DVI ports, and 1 DVI-D port. No other ports such as HDMI. I have the Acer P246H, and I'll be getting 1, and maybe 2 AOC 24" LED E2461FWH

System specs:
Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8.1 Pro, 64 bit
Processor: Intel(R) Core(TM) i5-4440 CPU @ 3.10GHz, Intel64 Family 6 Model 60 Stepping 3
Processor Count: 4
RAM: 16330 Mb
Graphics Card: NVIDIA GeForce GTX 760, -2048 Mb
Hard Drives: C: Total - 114370 MB, Free - 71123 MB; D: Total - 937971 MB, Free - 761923 MB; E: Total - 15793 MB, Free - 10004 MB;
Motherboard: Gigabyte Technology Co., Ltd., H87N-WIFI
Antivirus: Windows Defender, Disabled