Considering some hardware upgrades - new PC, and Echo Layla 3G to replace M Audio Delta 66

I have pretty much decided I'm going to upgrade my DAW a bit ti take better advantage of SONAR X1 than my old machine and interface are able to handle. I have an eight-year-old Pentium 4 machine running Windows XP with a M Audio Delta 66 and a MIDISport 2x2 USB MIDI interface. I can usually do OK with the smallish projects I usually work with (most often a bunch of MIDI tracks and just a few audio tracks) but it's hitting up against the limits, plus it's getting old and flaky and there are a couple of annoying things, like the Delta occasionally gets switched to a different sampling rate, and the MIDISport has taken to needing to reinstall its drivers on every reboot. I've read a bit through some earlier posts and it seems that some people are experiencing some issues with the Delta cards in 64-bit computers. I am considering a new machine with Windows 7 64-bit and an Echo Layla 3G for audio and MIDI i/o. Seems that several folks here have switched from an M Audio Delta to an Echo Layla and been happy. I'm wondering whether I should spend a bit extra and get an Intel coreI7 chip, but since I don't really record with a very large number of softsynths and/or plugin effects running, maybe I'm better off going with a coreI5 or coreI3 CPU and saving a few bucks. Any advice, anyone? Thanks in advance!

Thanks for your reply, batsbrew. But the Audiophile doesn't have the number of analog inputs I would like. The Delta 66, with four, was kind of a minimum.

I have an Echo Layla 3G and like it a lot.  I have never owned any other interface cards besides Echo, so I can't give a comparison, but the Layla 3G sounds great in my opinion - clear and detailed.  You could get a Gina if you want to save some cash, but it only has 2 analog inputs, so if you need more then that wouldn't be a good choice.  Keep in mind the Layla 3G only has a single MIDI port, so you would probably want to hang onto your Midisport if you need more MIDI ins/outs.  I have great luck with the 64-bit Midisport drivers, and have not experienced a problem.
 
As for motherboards, if you know what you are doing then I would say proceed onward - otherwise, you might want to get someone to help you out.  Don't 'cheap out', either - get the best you can afford now, because it's more cost effective to spend the extra now than to spend some now and then spend more later upgrading.  You won't get much for your nice, purty i5 processor on Craigslist when time comes to upgrade to an i7.  Same with memory - get as much as you can stand, and don't look back, because there's no guarantee that the memory you buy down the road will be matched with what you have now.  Remember, your requirements are what they are for now, but, as I have learned, they will change over time.  Pretty soon you will be running more softsynths than you ever dreamed, and will have an effect on every channel and or/buss in your project.  I once said "oh, I don't need all that stuff!"  Yeah, right.  Now I'm up to my ears in it.