lens - Choosing between Lenses Canon 70-200 f2.8L IS II vs Canon EF 70-300mm f/4-5.6L IS USM

I am considering between these 2 telephoto lenses but I cannot make up my mind on which one to buy. I have read a lot about the pro's and con's of both these lenses.. For example

70-200 f2.8 IS II

PRO's

• f2.8 across all range


• clearer sharper pictures with background blur


• excellent for indoor and low light photography

Cons

• bulky (1490 grms)


• price ($2,128.00 on Amazon)

70-300mm f/4-5.6L IS USM

Pro's

• Lightweight 1050 grms va 1490 grms for 70-200mm above Size


• easy to Carry as the zoom lense is retractable in size Zoom


• 100mm extra zoom as compared to the 70-200 which is excellent for wild life Photography


• Price ($1,499.00 on Amazon)

Con's

• f4 (pictures are not as sharp/ crisp as 70-200)


• May not be such a great camera for indoor low light photography

Lenses I currently own

• EF 24-105mm f/4 L IS USM kit lens for my 5D mark iii


• 50mm f/1.4 USM (which is great for indoor, low light photography)

Reason for my dilemma

On the one hand I like travel photography so carrying the 70-300 all day long should not be an issue as it is compact and reletively light weight.

On the other hand I intend to be go semi-professional i.e taking pictures for occasions such as childrens birthday parties, small family occasions (may be weddings some day) on a part time basis in which case the 70-200 may come in more handy (keeping in mind that i already have a 50mm f/1.4 USM

Could you experts please recommend which of the 2 lenses should I go for?

OR

Should I be looking at something completely different?

OR

Am I suffering from lens lust?