Alan, you MUST TRY THEM ON. Really.
You'll find that the fit of a good collar, which cuts the wind and keeps your neck and cheeks warm and dry, is a very personal thing. Ditto for a hood, big enough to keep the rain off but leave you side vision, and work with that collar. The rest of a jacket, the way the arms and wrists fit and seal or not, is less crucial but oh, the collar fit alone can sell you on a particular coat. The little features count, on the pants or bibs too. A crotch zipper that pulls UP instead of down, or a chest pocket big enough for whatever you want to keep dry, these things all have to be checked out in person.
I'm split between an ancient pare of Henry Lloyd that are not breathable (big demerit) and newer genuine GoreTex (which they will replace for free when, not if but when, it does leak) which is really just "camping" gear, but oh so much nicer in hot humid weather. If you're doing it for the first time, go for breathable with a guarantee, because it all gets porous sooner of later (5+ years) and the guarantee makes the replacement free.
Of course there's the reality of budget. I was lucky with my HL gear, got it 50% off because it was end of year and the styles were changing. But if you've ever been soaking wet, cold and miserable and stuck out on the boat, you'll come to appreciate why you want the best possible fit and performance, and if you need to rob a 7-11 to pay for it, just do it.