Diskless Workstation

Hi:
I need create a classroom with 13 computers without hard disks.
I are studie 3 cases:

1: diskless workstations (boot images of operating system with app: include
sql, vstudio, office, etc) DiskAngel is a good option but i need big RAM to
up a big image with SO and all app.

2: thin clients (using terminal services) good option but no use the
procesing local and need investiment in strong server.

3: diskless workstations (local processing) is the ideal, the better option,
but i can't how do it.

I decide for option 3 (know the network use) becouse we need use the local
procesing (P4 512 RAM). I like boot image of operative system for each
machine (reside in server) and use to all the other applications. Maybe need
central storage to use the app, or another idea that i no have now in mind.

I study the Windows Deployment Service to boot and install SO for network.
Too review windows xp sp2 embedded and i think that the last is the better
tool or any combination of both.
Please, i need any help or light to do this lab or classroom.

thanks in advanced
cyber