I used a neosport rental for my OW cert and found that in order to get it over my hips and chest I needed a size that was too big in the waist, shoulders, and way too long for me (I'm only 5'4" but I have an athletic build so finding wetsuits that fit has been a challenge) My LDS also carries Henderson thermoprenes and I tried one on and purchased my 3mm from them. I found my 7mm jane and jacket online and ordered it in the same size as my 3mm. The size charts were pretty accurate (I ordered a john and jacket and a 8/7 semi-dry for my husband based solely off the size charts and both fit him perfectly.) I ordered the same size jane and jacket, and the jacket stretches just enough that it isn't a problem. If you are in between sizes, i would say get the smaller jane and the larger jacket since it has to go over it. I know most online reailers have a number that you can call and they can help you find the correct size, and you can always double check their return policy just incase. There is a henderson rep on SB as well so they might be able to help you out.