Which NAS to buy

Hi

After a poor experience 6 years (!?!?) ago where I tried to run Squeezebox Server on a QNAP TS-101 NAS and got terrible performance, I'm looking to buy a NAS now.

What's the considered wisdom on which NAS to buy which will easily support my SB setup:

3 x SBS3
1 x SB Radio
2 x SB Boom
2 x PC-based clients

... usually these are all sync'd together but sometimes not; my collection is all FLAC / MP3.

Currently I run LMS on a Pent 4 running W2k3 Server.

Thanks