As far as tack goes, definitely wait until you have good measurements to buy, as luvmyperch said. Also, buy the best quality tack that your budget will allow. It's cheaper in the long run to pay a little more now and have good quality tack that can last decades with proper care than to replace cheap junk tack every couple of years.
That being said, a synthetic saddle may be a good option for you, especially if you don't plan on showing much. My sister has a Wintec western saddle, and I have and Abetta cordura saddle. Both have served us well for years now, and are about the best bang for buck out there for a recreational western saddle, IMHO. The cordura is cake to maintain, too. Hose, scrub (I scrub mine with horse shampoo and a dandy brush), and dry in the sun for an afternoon and you're good to go!
If you're set on leather tack, the only leather western saddle I've ever owned is a Circle Y brand Eq saddle. It's a really nice saddle, and fairly comfy for an older show saddle (given to me as a gift when I did more western shows, bought used). I don't know what the prices run on that brand now.
I personally like these kind of pads: Western Wool Felt Saddle Pad w/Wear Leathers
Kind of plain, I know (I think they look like pressed dryer lint, lol), but can be easily dressed up with a navajo blanket, etc., without adding too much bulk and overpadding. They mold nicely to the contours of the horse's back, with none of the stiffness I see in a lot of the (affordable) blanket-top "fleece" lined pads. My horse seems to sweat more under a synthetic fiber pad than with the wool.
Bridles are pretty much whatever you like as far as style goes. I personally like barrel or roper reins, though. Less to deal with than split reins, and less risk of dropping one, in my experience. Then, that might be the English rider in me wanting reins that connect
I keep 2 blankets handy, one quilted mid-weight stable blanket for winter emergencies, and one light canvas sheet for overnight before shows. If you know how to wrap, polos may be a good idea. If you're uncomfortable wrapping, splint boots or bootleg (pun semi-intended) SMBs may be a good investment.
Have fun tack shopping!