do most kits come with same yeast

[mat]

having read on this forum that most beer kits are made by muntons do most kits come with muntons beer yeast plain siver foil 5-6g packet. having just recived my latest order of beer kits brewferm diablo, Muntons wheat beer, edme superbrew gold weizen, morgans golden saaz pilsner all of them apart from the morgans kit looks like the same yeast.
I will be using safelarger s-23 for the morgans pilsner kit, so i will have some morgans larger yeast unused which i was thinking i could use on the weizen kit would this likley give me a better result.
one final question this is my first attempt using larger yeast the average temp i could ferment at would be 17-18c if i wrapped a cold wet towel around the fermenter do you think it would keep it to 15c. putting it out in the garage is another option but the temp drops to 2-3c even with a blanket wrapped around it i think that would be to cold.