The CX450M is much better than the Dynex, but not as good as the SeaSonic I linked, which also happens to be cheaper.
The semi-modular aspect is nice & all, but not as the expense of quality.
As for your proposed build, honestly, I wouldn't build an 860K + 750TI in 2016, it's just not a very viable setup and lacks any form of upgrade path. Also, pick up a 2x4GB RAM 'kit', not individually sold modules.
*EDIT* Nevermind. Canada, we get screwed up here.
I'd look to something along these lines for $600 CAD
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i3-6100 3.7GHz Dual-Core Processor ($144.99 @ Amazon Canada)
Motherboard: ASRock H110M-DGS Micro ATX LGA1151...