you could easily fit all of that gear into a box with a 10x8 face. 10x10 would be fine.
edit: I have an 8x10x6 box. 2 PIDs, 2 SSRs, several switches, outlets, power distribution, etc... it can all fit in there.
But, like others have mentioned... the 4" depth might be a problem due to PIDs as well as SSRs with heatsinks (if you plan to put the sink inside the box).