Will this be compatiable?

Hey there. I just want to let you know i'm new and looking for advice. As I am building a PC soon for around 320 pounds, I would like to know will this work fine as a casual gaming system (i am very picky with things like the motherboard, the case and the Power Supply Unit). Here are the specs i'm getting if possible -

Asus radeon hd6770
CiT 2017 Midi Tower case
ASrock H61M-VS motherboard
Crucial 2x4GB RAM @1333MHz
Intel celeron G530 @2.4GHz

1 Issue bugs me though. I need a power supply which wont explode or short circuit without reason. I like the Coolermaster extreme power 500W, the antec earthwatts 430W and the XFX pro 450W. But I see 750W PSUs at 25 pounds and it is an ACE black edition but I heard it is like a ticking time bomb.

What of the 4 PSUs do you recommend for the build?