The best horse is one that has been picked out by a trustworthy, experienced person. The best tack is tack that fits.
I know that's probably not the definite answer you were looking for but there is no definite answer. Get your riding instructor to keep an eye out for a suitable horse as they are aware of your riding standard and will have more connections. For tack, it really is the tack that fits is the best tack you can buy. That goes for any level of riding, but you can afford a more personal preference when you have gotten more used to riding. There is no point dropping 3 grand on a saddle if you might want to move up a gear with your horses at some stage, or you may quit horse riding (which is entirely possible given your relative new-ness to the sport).