The Toshiba would be a better drive, I currently use a 60GB 5400 and a 50GB 7200. I prefer the 5400 60 (the tecra that I use it in had the 40GB 5400, but I needed more space)
The seagate is nice too, but a bit louder. One thing to note, the Toshiba when it idles has a slight click to it, so dont freak out (this has been true of all their drives).
BTW: If you want I can sell you my 40GB, it was used for about 1 month before I got the 60GB.