Blueseventy Thermal Reaction wetsuit sizing?

Hi, I'm looking to get the Blueseventy Thermal Reaction wetsuit, and would like your advice on sizing.

I'm 5'6", 153lbs (Male).

According to the vendor's website, I'm either a Small, or a Small/Tall.

My concern is that getting this brand's size Small suit might be too tight and my arms and shoulders would get tired.

I'm aware that wetsuits are meant to be snug, and I'm not near any local stores where I can try them out.

I would like to hear of your experiences and suggestions with this type of wetsuit. Thank you.