What recommendations do you need? You are ready to roll a single iMAC for only $ 14 K, plus $ 4 K for some storage, and some additional items, so the cost per workstation is likely below $ 20 K. If your boss has that kind on money to spend, I would suggest he give you $ 15 K instead and you get him a $ 5 K PC and consider the rest a bonus. That is a WIN-WIN situation.
I'm putting the final touches on the two PC's I built for our office. Two high end Premiere editing machines for less than the cost of one comparable Mac Pro. We have 3 devoted Mac zealots in our office who were disappointed that the owner didn't go with the Mac Pro. Friday, I had all of the pieces laid out carefully and did run into a few snags. Nothing major. I used 2 Cooler Master Haf 932 full tower cases. I went with 2 Super Micro CSE-M35T1's. The Haf case had metal flanges in the front to support DVD/CD drives that prevented the drive enclosure from slipping in. I had to carefully bend the tabs down with a pair of needle nose pliers. I had to call Super Micro Tech support because their manual didn't explain where the other end of the activity LED's cable connects. Turns out that the cable is only for use with a RAID card. Once I got past that, everything went smooth. It was tense though. I think the disgruntled Mac guys were hoping the new rigs would go down in flames when I hit the power button. The pressure was on, and I always say a prayer before pressing the button. Fortunately both systems started first try and now I'm taking care of the details.
my new job is in an all Mac office.