WOOOOOOOOOOO big toopic starter there Dave. You are going to get advice from everywhere. I personally like the cliff keen micro mesh v-neck shirt alright, but I am sure most will tell you that the official's choice micro-softer mesh shirt is the best. As far as slacks go, I have cliff Keen's and they do me fine, but I hear the best is sansabelt. I wear a size 32 or 33 in jeans, but I ordered my slacks tighter with a 31. I know the cliff keen's fit true to size. like i said you will get feedback from everyone. so take what you want. by the way here are some websites where you can order some of this stuff:
http://www.refshop.comif you order over $100 or 125 you get free shipping.
http://www.purchaseofficials.com one of my favorites. I don't know why.
http://www.officialschoice.com
http://www.honigs.com
http://www.refandsport.com