I'm thinking of going down the watercooling route, not for any specific reason other than I think it looks cool (no pun intended) and would like just like to say I've done it which I'm sure a lot of people here understand 
Anyway, I've got a NZXT Lexa S case, a picture is available here of the space inside. What I'm wondering is how/if it'd be possible to fit everything I need inside the case, if it's not possible I have watercooling gromits at the top rear of my case, so no cut-and-shut, so if needs be I could place outside of my case (possibly on the top of my case, screwed into the 140mm fan slots?). I'm also looking for something budget but will keep my CPU relatively cool. Yep, I'm asking for a lot
I've read bits and pieces online, but I'd like to get some opinions on here as well before I decide to do anything.

Anyway, I've got a NZXT Lexa S case, a picture is available here of the space inside. What I'm wondering is how/if it'd be possible to fit everything I need inside the case, if it's not possible I have watercooling gromits at the top rear of my case, so no cut-and-shut, so if needs be I could place outside of my case (possibly on the top of my case, screwed into the 140mm fan slots?). I'm also looking for something budget but will keep my CPU relatively cool. Yep, I'm asking for a lot

I've read bits and pieces online, but I'd like to get some opinions on here as well before I decide to do anything.