[Pulse]

if you want runtimes go for higher voltage

I don't know the rules in UK but here we can run 6 cells and it's much more efficient

the s350 is an excellent car and you could use two 3s lipos with a 1400kv motor and get more runtime and less heat than any 4s setup

if you want to keep it 2x2s, use a 1700 to 1900kv motor, the tenshock are cheap and good

or a used tekin 1900..

for the esc you don't need more than 120A, everyone saying the contrary isn(t setting his car right, the xerun sct 120A is perfect for this application: cheap, smooth and reliable (in 4S only)

I even ran a mamba max pro in 6s this summer on my durango with a 1400kv t8 and we did a 12 hours endurance with it without failure (this esc is rated 100A which is perfect in 6S 1400kv)

runtime: 20 minutes on a big track with a 6s 3300mah lipo (500 grams)

for the batts gens ace or nanotech: cheap but good, no need using hardcase though they are heavier, more expensive and when the lipo gets a bit bigger (they always do even if with a good charger and storage) the case cracks..