The Brick has both machines and free weights, lots of them. Tho floors and lots of exercise bikes, etc. They have showers, not sure about saunas.
2,800 baht monthly. Not the cheapest but a very modern gym. They also have a restaurant with protein shakes and healthy meals, etc.
Also many personal trainers on hand. 5,000 for 5 one hours sessions and three extra sessions thrown in for newcomers.
The gym is never really crowded and the m,ix is about 70% Thai and 30% farangs. Really pleasant staff and stunners on the front desk ????