i am far from an expert, and ive only played zone once in d1. i took a mid major (csun in tark) to the elite 8, over the course of maybe a 7 season rebuild, where i lost by 3 to a team so much better than mine, they had to have 9 of the top 10 players (and arguably the top 5).
however, i really thought i had things pretty well figured out at the time, it was a fb/zone set. the trick to zone is to make sure you get guys worthy of playing 35mpg, and play them that 35m. you can't have a well rounded team, unless its very short, or else zone suffers somewhat considerably, it seems. you really need to find a couple guys who are tip top scorers (for whatever set you had, my super star on my fb/zone set had 70 ath, 100 spd, like no lp, and 48 per, with 99 bh. he also had a+ ft shooting and that led to his greatness, he put up 24ppg even against top competition, at very good efficiency - really, he outperformed many, many 90 ath/spd/bh/per guys ive had over the years).
along those lines, i think zone really rewards teams who build a good starting 5, from a synergy standpoint. those 5 guys will play together more than starters in any other set. so if you can manage to grab a great pg in a traditional (spd/bh/pass/def) sense, a great scoring sg, 2 great rebounders, and a sf who rounds things out in whatever way is needed, you can play the **** out of those guys, and really claim an advantage over other teams who are playing their backup line for 15 minutes a game.
i found that bigs had to have good reb/sb (which go hand in hand) to be effective in the zone, with at least competitive ath (60+). defense is still very important in the zone, i think that forum myth doesn't have the wings it used to have, but you still hear it from time to time.
still, arguably the best advice i can give you is, always take a couple walkons. in zone, you really rely on your stars. ANYTHING you can do to up the quality of your top few players, do it, even if it means taking 2-4 walkons every single season. i wouldnt take less than 1 under virtually any circumstance, and really would only take 1 if i was thrilled with every single player i signed. also, consider the use of senior transfers for that 7th-9th spot, i mean they aren't great a lot of time, but then you get the money right back (same as a walkon), and often, they hardly play anyway, and even when they do, they are usually at least competitive with the kind of freshman you'd have signed as your worst freshman.