NP5165 Secondary HDD & WiFi Card Upgrading Questions

So my older NP5165 has still been going strong for 6 years or so now. After quite a few upgrades (Full Gamut v.4 screen, Samsung Evo 500GB SSD, i7-2760QM processor, 16GB RAM), I'm looking to upgrade the second hard drive and WiFi card.

Current setup:
Primary - 500GB Samsung 850 EVO SSD
Secondary - 500GB 7200 RPM (Serial-ATA II 300 - 16MB Cache) in the optical bay
Additional 1.5TB scattered on 3 external drives (1 TB USB3.0, 2 320GB USB2.0).

I'm looking to upgrade the space in the machine to consolidate my pics/videos and not deal with 3 external drives kicking around.

I'm looking to either install a larger 1TB 7200 RPM HDD or 2 TB SSHD (w/ 5400 RPM HDD) in the secondary optical slot and sticking the old 500GB in a dock or USB 3.0 enclosure; OR just buying a 4TB USB 3.0 External drive and consolidating all of the smaller drives in to one, with plenty of extra room:

1TB 7200RPM HDD options:
#1 - $71 - WD Black 7200 RPM SATA 6 Gb/s 32MB Cache 9.5 MM 2.5 Inch - WD10JPLX1TB https://www.amazon.com/dp/B01DOL05O...lid=26WC9GYZBNR56&coliid=I2ARWKIRZ276XY&psc=1

#2 - $64 - HGST Travelstar 7K1000 2.5-Inch 1TB 7200 RPM SATA III 32MB Cache Internal Hard Drive 0J22423 - https://www.amazon.com/HGST-Travels..._feature_keywords_three_browse-bin:4990425011

2TB SSHD Option
#1 - $122 - Seagate FireCuda Gaming SSHD 2TB SATA 6.0Gb/s 2.5-Inch Notebooks / Laptops Internal Hard Drive (5400RPM HDD) (ST2000LX001) - https://www.amazon.com/dp/B01M1NHCZT/ref=psdc_1254762011_t2_B00MPWYLHO

4TB USB 3.0 External HDD Options:
#1 - $117 - WD Black Passport https://www.amazon.com/Black-Passpo...eywords=4tb+external+hard+drive+usb+3.0&psc=1

#2 - $119 - Seagate Backup Plus 4TB Portable External Hard Drive with 200GB of Cloud Storage USB 3.0 Black - https://www.amazon.com/Seagate-Port...=8-3&keywords=4tb+external+hard+drive+usb+3.0

My questions are: 1. I've heard the optical slot only uses SATA II (3.0GBPS) vs SATA III, can anyone confirm this and if so, what difference does this make with the 7200 RPM vs 5400 RPM drive and/or SSHD being there?
2. Which would you recommend for the most storage at the fastest speed.


Second, I'm looking to upgrade the Wireless Network Intel® Advanced-N 6230 - 802.11A/B/G/N Wireless LAN Module + Bluetooth with a newer/faster module. The two options I see are:

 

1. Yes, your optical drive port is rocking SATA Gen 2. This doesn't make much - if any - difference with even a 7200 RPM mechanical drive insofar as performance is concerned, although SATA Gen 2 is lacking some features found in Gen 3 you may or may not care about. See here for additions to the Gen 3 revision.

2. You won't get much out of the optical bay, so if it's primarily a storage issue, as it sounds, then go with the 2 TB/5400 drive. The 1TB will be a bit faster, but not much. You could throw a big SSD in there, but obviously it won't operate as well as it can in a SATA II port.