0.30 or 0.50 mm latex sheeting? US Shipping

Hiya! Fixing to try my hand at making my first latex garments. I'm in the US and planning to order from MJ Trends for starting/practice materials (& later from likely Radical Rubber or Euro Catsuits once I know what I'm doing). MJ Trends doesn't have much selection in 0.40mm sheeting . I would need to buy 0.30 or 0.50mm. I'm wanting to make underwear, a pencil skirt and some collars. Would you go with the thinner or thicker option? Any and all advice is more than welcome!