Laptop help

Hey, im buying a custom laptop off pc specialist because i bought a PC there two years ago and i've had no problems and i think it was a good deal.

The laptop is for university this september. Besides the obvious need of storage, i do game a bit (steam games like csgo, l4d2, terraria).

Questions about current specs:

CPU - i5 duel core 4210H (2.9 // 3.5 turbo) -- is the i4720HQ worth the £100 more?

RAM - 8GB kingston --- is the 16gb worth it? i heard it creates too much heat

Disk Drives problem > ive never had an ssd before, my friends said i should get one and try it out for the laptop. The laptop cannot have 2 drives, but i can have 1 drive and a m.2 SSD drive...

1. do i go for 1 SSHD hybrid drive // or a HDD + an SSD in the m.2 drive // or a SSHD and an SSD??? im naive sorry!

2. the HDD options are

.1TB WD BLUE 6 Gb/s 1000 GB 5,400 RPM 8 MB

.750GB WD BLACK 6 GB/s 750 GB 7,200 RPM 16 MB

3.the hybrid is

.1TB MOMENTUS XT HYBRID 6 Gb/s 1 TB 5400 RPM 64 MB

4.for SSD's kingston...

.120GB KINGSTON SSDNow M.2 2280 SATA Rev. 3.0 (6Gb/s) 120GB N/A N/A 550MB/s 520MB/s

i doubt ill get a 240 due to cost so ill leave it here.

Thanks sorry if this is too hard to read or poorly written, just msg and ill try clarify