GH I've ordered from Victory Canter in the past and it's a crapshoot. I've gotten my things extremely timely and I've had it take f.o.r.e.v.e.r and a bazillion e-mails before I got them.
Annoying part was that the "nice to have but certainly not a necessity" items arrived fast but my girth? I was screaming mad before it finally arrived! I wanted to ride my new horse and couldn't until my 18" girth arrived since the absolute smallest dressage girth I could find locally was a 26".
I can't help you on sizing, I've never ordered anything in that brand before.
I ordered from Victory Canter several times (pads and reins) and always was pleased with service, price, and how fast it was delivered. I also had no problem returning and exchanging the wrong size pad.
My shirts arrived today and I LOVE them. They are quite generous in size, and are also lightweight and stretchy, and no buttons on the front, not going to scare the judge by pinging a button off of my chest while trying to halt somewhere near X.
I bought this one
And this one, only in white and blue
Hopefully they colors won't show under my jacket, and if jackets are excused they will hopefully still be appropriate attire. I'll update when I've worn and washed them a while, but so far they get a big thumbs up