Got the new machine built and running.
I reconsidered the RAM and went with 16GB RAM instead of 8GB. The i5 processor I went with is pretty high-end (for an i5). So I didn't want to hinder the performance of the box by shorting it on the RAM. And 16GB is the max for this motherboard (cheap motherboard).
I am using a 120GB SSD as my boot drive and a 1TB HD for extra storage.
I had to send the original case back and get a replacement. A number of the plastic tabs that held the front panel on were broken. Luckily there was no issue with the RAM (I was worried). NewEgg was very good about it.
The internal wifi adapter I bought proved to be very problematic. It had significant driver issues with Linux (and Windows too according to the unfavorable reviews). So I opted instead for a wireless bridge. That way all I need to deal with is the wired LAN adapter. I got a 4-port dual-band 802.11n bridge. It will connect our whole office to the router in the living room. And I even managed to position the two so that they are pretty much line-of-sight with no obstructions. That should be quite reliable.
After a lot of back and forth I decided I will run Fedora on it. I know I change my mind on this sort of thing almost as often as my underwear, but I'm hoping to sit still on this choice for awhile.
One of the problems with the Haswell chip on-board graphics is drivers. That chip is so new that a number of Linux distributions do not support the graphics on it yet. I was initially going to run Debian. No support. Then I thought it might be a lot of fun to run FreeBSD again. Got it all installed. No support for my graphics.
I could run a *buntu derivative, but I figured Fedora should be fun. Arch would be ok, but I don't really need that level of frustration with getting basic things to work. So Fedora it is.
After placing my order for the new machine I decided to sell a few things on Ebay to offset the cost. The processor I went with was about 4 times the price of the Celeron I was initially going to go with. And changing my mind on the RAM cost a bit as well. So I sold my recently-purchased Chromebox and my Kenwood hand-held ham radio that was rarely-used.