RME Fireface 800. Your right, it is pricey, but I love it. Found mine on Ebay at a discount. Totalmix is a little different but very cool. Takes a little getting use to, but I love this unit.

RME Fireface UFX is your best choice. It works beautifully in Sonar X2a and either Windows 7 x64 or Windows 8 Pro x64. It doesn't require a PCIe slot and it comes with two great pieces of software, TotalMix FX and DIGICheck.

Tom Riggs
Yow have good options with the suggestions you have already.
 
I am using a RME Radat card but it is pcie.
 
I would suggest that if you are about to spend good money on a new card perhaps its time to consider a computer upgrade to use a pcie interface. Pci is fading fast and there is a good possibility that the pci card you buy now will have to be replaced again when you have to replace your pc.
 
Just something to consider.

I think I would rather have a sharp stick in my eye than to set up a new computer.  

Hey Dave.
 
Here's a deal on a RME Fireface UFX.
 
http://vintageking.com/sale/demo-deals/rme-fireface-ufx-demo-deal
 

consider also  ALESIS I/O 26...2x ADAT....firewire

Just to remind you...If you keep the UAD card in there, Mod Bod...You might have to go USB.....Like I said before...IRQs...wink wink....or Apollo dual setup or something like that that, which removes the need for the UAD card completely....I believe?
 
If you go out and splurge on next gen audio devices of similar slotted ilk adding another USED IRQ of the no remaining mentioned, and continue to use UAD card along side, that takes up another Irq .....You are only asking for similar problems, as you are not addressing the issues correctly I pointed out...That may be causing your problem to begin with, and if you go PCIe x1 or x16 if they make em, or any slotted card (firewire card and firewire  audio device attached and UAD) you only make the same bed as you already have now in play....Just look at my specs...see a UAD card in there?...and it says it does not work at the end...so I did my research...many others might have issues like this that use UAD and another card in a second slot along side...If you look that is through the forum posts, and others with BSOD problems...You may see a patterns of multiple cards installed in said systems.....leading to IRQ sharing/BSODs results, and not turning off things in bios to free some up, and turn off potential problem causing devices with some audio Drivers...and windows 7 mismanagement of them in sharing,...one card per system works better...is my understanding / and tested over these last months, to prove the culprit is the UAD sharing with a chipset or vital system device controller/ and causing conflicts with audio devices or drivers cpu request and such, while win 7 reports all is working properly in device manager......So USB and UAD might work better than what you are using now, and or what you think you want to replace and pair it with....and not Going USB.
 
Have you tried that solution I mentioned ,and Yank the UAD card and remove the drivers?...and test that audio card you already have with sonar x2 solo...to see if the problem persists??
That could help you make better choices before you buy anything Yet....Wink
Remember  going  in circles starts by overlooking, and not trying different solutions, which will only take some time to put back and try something else in reverse ..Losiing hair starts by being mislead down many paths to  continued BSOD.
 
So take care, and research the IRQ issues even being posted on MS win 7 wed forums...By testing what you got..and removing parts to check where the problem really lies.(Process of elimination)..or You will have a pile of audio devices piled up like me.....wink....
 
Just saying....and trying to save you some bucks...before you lose hair!...and sleep...and slowly your mind......Wink....LOL
Blessings!
 
And Good luck!
 
Sir Les

I have a terratec EWS88D. Windows 7 drivers too
It has 8 channels of ADAT Lightpipe, Midi, and stereo S/PDIF
 
I used two in my windows 7 machine when I was running the studio commercial but have since
backed down to one of them so I have one available.
 
They work in ASIO Mode in Sonar quite nicely

bapu

Mod Bod
I'm thinking RME because they've been around and seem to be moving along with the times.  If you are using RME, tell me how it's working with SONAR.

 
Fireface UFX user here.
 
Rock solid.
 
I use the usb cable (no slot required).

+1

Dave, a further option I'd forgotten to mention earlier which might also replace your Dakota would be the RME Digiface + HDSP PCI host card. Basically equivalent to the HDSP 9652 but occupying only a single PCI slot and having all the I/O on the external Digiface breakout box.
 
http://www.rme-audio.de/en_products_digiface.php
 
http://www.rme-audio.de/en_products_hdsp_pci_interface.php
 
In case you upgrade to a PC without PCI slots, you could just replace the HDSP PCI host card with the PCIe version while continuing to use the Digiface.