50mm and 135mm actually differ a lot? 

if its me 17mm and 28mm is more crucial. furthermore, 17-50 is 2.8 constant

anyway its up to how you use your lens

have a deep thought on what you gonna shoot 

who poisoned you that can only get crisp amoi pic using prime? zoom lens can also ma
if wan sniper amoi then zoom lens better lo, coz sometimes amoi near, sometimes amoi far

anyway, do you hear whispers of a 50mm or 85mm prime?

If I may, what do you think about having 24-105mm f4L? Gives you the range, as well as the constant aperture. I know it's not in your option, but just in case you haven't considered it.

A little misconception there. portrait isn't all about background blur/ bokeh. face expression/lighting/composition/background elements/ posing play a more important role imo. everyone can create blurred background as long as they have big aperture lens (f1.8 or something), but this doesn't mean good picture.

that being said, even with f4, at 105mm you can still produce blurred background.

for example shots like this (little NSFW due to lingerie) https://500px.com/photo/84753749/anastasia-...m=popular&only=

can still looks awesome with proper lighting and not so blurred background.

but if you are a big fan of bokeh, then the 24-105 might not be the best lens for it. shots like that look good too, but a lot of the time the picture is only left with a lot of blur, that's all.

my 2cents.

EDIT: more portrait with clear background.

https://500px.com/photo/84729045/us-by-espe...m=popular&only=

https://500px.com/photo/84724095/whitehair-...m=popular&only=

get a flash for event photography and you can see a different result

i like bokeh too

but bokeh depend on your subject distance from bkg, from u... aperture... focal length... so even a 50mm 1.2 wont give the bokeh u wan if model standing too far away...

so now you got to think, where u most likely take the portraits - indoor ke... outdoor - this will determine your focal length... how far you stand if need full body shot... etc...

so i would suggest you bedah siasat step by step, imagine your scenario and then you start to know which focal length to go for... coz wide aperture lens are aplenty 30,50,85, 135... they all have different ways to use and usability...

definitely flash is important, even for outdoor. coz backlight can be a problem... but depend on your style also... some ppl like to shoot to take out background completely... but then again... bokeh tak nampak lo... furthermore, do you use M mode? if not... more headache to tell

just consider flash in your decision making

donno where to aim then aim forward, which is the obvious position.

Just a heads up, Canon prices are going to increase by 15-20% on 1st Jan. So anyone on the fence on buying Canon gears better do it soon.

wei, earn your own toys la 

haha that old version also i cant afford