Selecting correct size Underworks

[Brandon76]

If I wear an XL t-shirt should I get a Small, Medium,  Large, or XL Underworks ?   I have a bad case of gyne (worse than the pics I have seen on here)  chest size is ~46 inches.  Right now I am using ducttape (for the last 3+ years), and need to find another option.

Also, any feedback on the new Tri-top Chest Binder
Style 983 ?

New to the forum....it has been a real help already!  Its nice to know there are realistic options for me ie trying to get Kaiser to pay for it, or going to TJ to get it done if needed.  

Thanks!

[RDS8500]

I have 5 Underworks 997's. I order and wear the same size that I wear in a regular under shirt and they do exactly as they're supposed to do.