what wall Tile adhesive and Grout?

GT60

Hi I need advice on what tile adhesive and grout to buy and have been looking at bostik and Norcros products on another web site as i can seem to find anything for a shower / bath area that dries in 24 hours so i can carry on working and use the shower.
Bostik Smooth Finish Tile Grout J100 3.5kg White https://www.wickes.co.uk/Bostik-Smooth-Finish-Tile-Grout-J100-3-5kg-White/p/171199
 / Norcros Universal Standard Setting Tile Adhesive https://www.wickes.co.uk/Norcros-Universal-Standard-Setting-Tile-Adhesive-White-10kg/p/167673 https://www.toolstation.com/mapei-flexible-wall-floor-grout-25kg/p28505 
https://www.toolstation.com/mapei-fast-set-wall-floor-tile-adhesive/p46605
or pre mixed 
Bostik Ready Mixed Tile Adhesive & Grout A175  https://www.wickes.co.uk/Bostik-Ready-Mixed-Tile-Adhesive+Grout---5L-White/p/167968
Bostik Non-Slip Ready Mixed Showerproof Tile Adhesive A100  https://www.wickes.co.uk/Bostik-Non-Slip-Ready-Mixed-Showerproof-Tile-Adhesive-A100---5L/p/167963

Please can someone advise me on whats best and i only need small amounts i think and can i use a grey powered mix to stick white tiles and save some money then white grout?
Thanks

GT60

Update 

The tiles are 20 X 25cm and a max of 40

The 24 hours is just a guide as I've read pre mixed stuff can take a week to set.

But the two Bostik pre mixed links says 24 -48 hours in the specs on the Bostik web site

The grout area will be around 50 tiles all depends on how many may need removing.

Any advice would be great

Thanks

TELLIT01

Drying time will be dependant in part on the temperature and humidity.  Given the current weather I would err on the side of caution and not use the shower for at least 48 hours is that is the range given for the adhesive or grout to dry fully.

tacpot12

Don't use a ready-mixed product as they cure by drying, and will need longer than a product that ships dry and cures when you add water. If you use a grey adhesive, you will get grey areas showing through the grout lines, so you really need a white adhesive for best results. I've had good success with Mapei products so would recommend Mapei Keraquick S1 Rapid Set adhesive as you can get this is in White and in packs as small as 5Kg. This sets in 24 hours. 

Mapei also set a fast curing grout that will be ok to shower in after 24 hours, but the more time you can give it (upto 48 hours) the more hardwearing the result will be. Last time I did a tiling job at home, I warned everyone that the shower would be out of action for two days, one to do the job and a further 36 hours to dry.