I meant to respond to this last night but got sidetracked...
For that house, I would bet a single UAP-Pro or UAP standard will work great if placed correctly. I too have a pretty central kitchen and just put one on top of my kitchen cabinets and I get excellent coverage everywhere (1 UAP-LR covering 2 stories, 4,000sq ft and my yard + some distance away).
Whether or not to go 5Ghz - I kinda figure why not... it just gives you more bandwidth to use. 5Ghz though doesn't have nearly the same penetration as 2.4Ghz so if you were trying to scale out 5Ghz more, you
might need two - but personally I wouldn't worry about that any time soon. The low penetration is also why it appears to have much more room in the spectrum - even if your neighbors use it, it won't penetrate the walls as well. Most of the time I actually use 5Ghz, it's for backhaul between radios to keep 2.4 clean.
For people who have the Pico's, if you want to move to UniFi, you can - in Ubiquiti's Unifi forum, they have a link to a special version of the Pico firmware to convert it to Unifi; this can be great if you want to upgrade to a new WAP in the house and toss the Pico outside for coverage in the yard and they'll work together - or even use the wireless backhaul if you want. Another nice thing with Unifi is it supports multiple SSID's (up to 4) that can each be configured differently - different security, guest mode isolation, even different VLAN's (that's where a netgear prosafe switch comes in handy) and even a built in payment portal and walled garden you can use if putting these in public spaces.
As far as the price - knowing what I know about the Ubiquiti supply chain, I don't even know how SolidSignal can buy them anywhere near that cheap - let alone sell them at that price. But, I've bought through them before and worked with them plenty of times - and believe them to be a good reputable company - so if that's accurate, I'd jump on it.
Powering the AP's - they always come with a passive POE injector - these are dumb injectors that just dump 48v power onto the pairs with no intelligence like 802.3af POE - but they are also compatible with regular POE switches and injectors as well. Netgear has some prosafe plus switches that have VLAN support and four POE ports - pretty handy for stuff like this. Now all that's specific to the UAP-Pro; the other UAP models use 12-24V passive POE only; if you want to power them off 802.3af they sell an instant POE adapter that's just a little pigtail that goes between the switch and the AP (same with their cameras, radios, and mFi platform) and they come in indoor and outdoor forms.
The software runs fine on Windows, Linux or Mac - it's Java based. I have instances of it running on Debian on an amazon cloud instance; another running on a debain micro PC; I run my own on my mac laptop and only fire it up to make changes; and I've run it on server 2008R2x64 and 2003 WHS - the only time problems crop up is if there's an issue with your java installation. By default it doesn't install as a windows service but there's info on fixing that.
And for BSR - the outdoor version of the UAP is 2x2 MIMO - even with the two stock rubber ducky antennas, I've managed to get a usable connection from just over 1400ft away from one (all outdoors) - talk about impressive range! I also have a 13dbi polarized directional omni that I can attach - but I haven't found a space big enough to properly test the limits of that one without running into other obstructions or ack timeouts.
I do know the Ubiquiti brand pretty well... I've installed a LOT of their equipment in a lot of environments. I've used Wifi since the very beginning (back when a Wifi PCMCIA card had a 30ft range and cost >$300), but things have evolved, and I've spent the last 18 months or so doing some hardcore wifi engineering and learned a lot more.
