I have Mountain Horse boots, both in leather and synthetic and I find that Champion hats fit my head shape.
My OH lives in various Ariat boots, which she finds at bargain prices (that's what she tells me) on Preloved and Ebay, she likes GPA hats, as they fit her well, although the sizing can be a bit odd. I have a GPA and although it fits well enough, it's not as comfy as my Champion's.
Hats are definitely one of those items you need to try before you buy.
I have ariat bromonts for shows and just some Dublin ones for the yard (mainly wear my hunters around the yard). I have just had to replace my hat but got the same one I have had for 7years, a champion ventair one... Comfortable and smart and doesn't break the bank, my last one lasted me 7yrs and only replaced it a couple of months ago after knocking myself out falling off!
I have toggi jodhpur boots for everyday work that have lasted me a good 4 years without being cleaned (woops) and are still as comfy as when I got them, and MH venice boots for going out and about. Also have a champion ventair but hoping to replace with a Charles Owen or Caldene, its a lovely hat good price and comfy but just not for me
I have the Ariat Heritage Contour Field boot for shows (which are ridiculously comfortable for riding in, but I don't recommend walking in them too much, I think that's the point though!) and some Toggi paddock boots with Ariat Concord or Eqvvs Synthetic leather half chaps for day-to-day use. The paddock boots are perfectly adequate but I am saving for a higher quality pair (either Ariat or Dublin), and obviously the Ariat chaps are more comfortable and harder wearing than the Eqvvs ones, but for only £30 there absolutely nothing wrong with the Eqvvs ones and they've lasted me a good couple of years.
As for hats, I currently have the Gatehouse Air Rider hat, which is fine and lovely and light to wear, but it was a quick buy because I needed a hat and didn't have much funds at the time. For shows I actually borrow my mum's Champion Air-Tech (as we have the same size head), just because it looks smarter as it's all black. If asked though I would have to say I'd prefer a Charles Owen, either the APM II Skull cap or the 4Star as I like the look of them and the level of protection they give.
for home i have a casco mistrall which i LOVE, so light and comfy and the dial will adjust depending on whether ive got hair up in a bun or ponytail etc.
boot wise for home i have Donadeos in dark brown with a patent snakeskin trim round the top.
for shows i have the navy KEP with glitter panel with again i love, really comfy and blingy! then the same donadeo boots in patent black.
For everyday I have the Gatehouse HS1 jockey and Mountain Horse Johd Boots and Ariat Chaps, or Mountain Horse Paddock Boots, for shows I use Charles Owen velvet cap and Ariat Bromonte but I went for the plain front this time and not the laces.
I have the waterproof Ariat jodhpur boots that zip up at the front and I team them with some half chaps. I have a Just Togs velvet riding hat and a Caldene vented one.
I have broginis for riding (older ones they seem to have gone a bit cheap now... ) mountain horse yard boots (the long ones with the fluffly linings ) for yard work or woof wear cheapo ones for the summer. hat wise I've got a gatehouse RXC1 for every day and a Charles Owen 'Fiona' hat for showing...
Charles and Owen Junior Skull cap, fits my head reasonably priced and I've worn them since I started riding Boots, am currently riding in my walking boots and neoprene chaps keeps my legs warm and dry and I can't afford to replace my old boots at the moment.