The obvious choices here (some of which will be way more relevant than others): **SuperUser**, **Software Recommendations**, **StackOverflow**, **Server Fault**, and **Raspberry Pi**.

There could be a few more such as Database Administrators that might find some use here, but I see DBA as a strongly software-oriented site that won't need much from a hardware site.

Alternatively, we could aim at absolutely any site involving technology, whether it's hardware, software, programming, etc. There's bound to be people out there somewhere who will notice our ads and be interested because they just need a replacement laptop or something. The possibilities here are endless.