[mjevans]

'completed server systems' maybe? Something that makes it clear it is a complete computing device, not just the core component of one.

[Hamuko]

I would've gone with "prebuilt servers" or "rackmounted servers". Those are of course simplifications, but would make it a bit clearer that it's referring to specific server hardware and not servers entirely.

[dizhn]

That would sound either like they are selling custom servers or kits, or they are selling servers in other form factors like towers which both Dell and HP have.