n-Track writes directly to disk. If you read the FAQ written by the author, there is little benefit to memory above 64MB....if that's all you're doing. Of course running NT and Win2000 might like the extra RAM. NT4 takes 32MB right off the top. But I'm running NT4 on 64MB and have never had a memory related performance problem running n-Track.
Realize that you'll need a 370 to Slot1 adapter if you're going to run that Celeron on a BE-6 mobo...that's an additional 15 bucks. Right now, however, I would avoid the Celeron because the prices on PII processors have really dropped. You can find a PII450 for $110 if ya look hard enough. It will outperform the Celeron.
Don't blow your money on Kingston memory either. I have never bought anything but generic memory and have never had a single complaint. You're not running a mission-critical application here....n-Track will crash on its own without any help from hardware

You can find 128MB unbuffered non-ecc stick for the same price as a name brand 64MB stick. That'd be the way to go. Don't get stuck like I did....I was thinking "I'll just add more memory later"...and suddenly the prices tripled and stayed that way for many months. Now they're back down unless you're buying the "good" stuff. Get it while it's hot.
AND, don't blow your dough on that tiny little hard drive. I didn't realize that they made em that small any more. A 13GB 7200RPM Maxtor can be had for $129.
And, don't bother with SCSI. You should see decent transfer rates in the 50MB/sec range with a 7200RPM ATA/66 drive (closer to 66 depending on the chipset). SCSI will get you 80MB/sec (actually up to 120 now) but you're going to pay 3X more which is not worth it. There are plenty of articles out there on the pros and cons of SCSI vs. EIDE in recording applications. Do a search. You'll hit the cost vs. performance intersection just right with ATA/66.
Finally, you might as well get the BE-6 II which has been out for some time now. I'm running the BE-6 and it's fairly decent. Had some troubles with the Highpoint UDMA controller but resolved it by obtaining current drivers & BIOS upgrades.
If you're set on the Celeron then consider your overclocking options. The faster your processor the less likely you'll be able to overclock it. CPU Speed = bus speed x a FIXED multiplier. My 400Mhz Celeron is running nicely at 500Mhz via an 83Mhz FSB.
Have fun. (BTW, your choices are fine. I just think you're limiting yourself a bit. Better stuff can be had without spending much more)
Slackmaster 2000