For the Sans digital box your pretty much limited to various marvel chipsets, sil 3132, and asmedia 1061, all sata and they need to support FIS based port multipliers, I've found for single drive performance the asmedia tends to be the best but for multiple drives marvels hyperduo based cards...
the 290x can draw 350 watts by itself when overclocked, but stock if you don't enable uber mode it should work although you may need to lower the power target and you are maxing out your PSU
I went from a Xeon 3060 w/ P35 asus board to an X38 E8400 Rog Asus board then my current X58 Evga board which has seen an I7 920 D0 and now an X5650 B1 Xeon all on the same Win 7 x64 Pro install from 2010
I'd say my longest lasting card is my current EVGA GTX 480, I've had it slightly over 3 years, honorable mention goes to an EVGA GTX 260 Core 216 that was in service since 2006 / 7 ish in my main pc and then given to my brother who still used it till last year.
If reliability is the #1concern then it's too soon to recomend any 5TB drive and of those listed I'd go with the 5400rpm hgst drive.
Note the hgst and Toshiba 7200rpm drives are almost identical.
You could try the Antec P280 or the Fractal R4. The R4 might be a better fit if you add a side fan.
Edit : you could also try the Fractal define XL R2 it's a bigger version of the R4.
I have 4 x 2TB HDD's on my main rig
2 x hgst 7k2000's, 1 x WD Black faex drive & 1 x Toshiba 7200rpm drive.
Also 1 x Ssd a crucial mx100 512 GB drive
My server has 4 x 2TB HDD's + 1 1TB HDD & a 60GB SSD.
I've had a Seasonic S12 600 watt unit in service with 3 different PC's since 2004 and a PC power and cooling Silencer 750 watt unit since 2007 both are still going strong in current PC's and have been through 3+ PC's each.
I had an Antec 300 v2 that one of the stick on rubber feet fell off and got lost, I contacted Antec and after verifying it was still in warranty they sent me 2 for free within 7 days :)
Intel PCI-E NIC's have much much better support (drivers & OS support) and mostly lifetime warrenty's so you can carry it from system to system and they tend to have better latency and bandwith vs Realtek.
I've had the same Intel Pro 1000PT PCI-E NIC in my system since my Athlon 64 3200+ and...
a card based on this chipset is the best option for cheap 1x controlers, it has the best performance of cheap 1x cards
to get better you would need to speed 5x as much as one of those cheap cards.
A Geforce 210 is the cheapest fanless card I could find the last time I looked.
http://www.amazon.com/EVGA-GeForce-Passive-Graphics-512-P3-1311-KR/dp/B004KABG22/ref=sr_1_3?s=electronics&ie=UTF8&qid=1353011177&sr=1-3&keywords=fanless+graphics+card
that is $23.99 after rebate
It might be cheaper to put up towers / masts to get LOS for wireless than to run the cable 10 Km if where your putting the masts / towers can give you line of sight and it's not aganist the zoneing laws where you're located.
I would just use you main PC as a back end for streaming to your TV the 360 works fine as a media extender, just run something like PS3 media server on your main PC and add the 2 1.5 tb drives and you should have enough space.
The 2700k is more than enough to transcode on the fly to a format...
I have the same Motoroloa SBG6850 and it's been great a a modem, but it is a truely teribble router / wireless device. Use your own wireless router and turn off the routeing features of the SBG6850 by putting it into bridge mode and you will be much happier. Personally I have a 30/5 connection...
I'd have to say the biggest wow factor I got was going from my Matrox G200 8mb + Orchid 12mb vodoo2 card to my Diamond Viper 550 TNT 1 card w/ the Orchid card for gilde games still, the first time I saw 32 bit color in 3d was amazing :) for longjevity I'd have to say my Visiontek Geforce 4 Ti...