If your account is big enough , you can probably get one of the big boys to buy you anything you want, as long as you promise to trade daily.
How many trades you doing day? Are you using market orders or resting stop and limit orders? If you are low frequency and not using market orders then you can use a home setup with a mid priced PC.
No, you don't have to. Regular day trading or swing trading algorithms work fine to run from a server at home. Low latency strategies is not for retail traders and should avoided. An regular PC with 16GB memory or more and a CPU with 4-8 physical cores work fine as a server.
Have you factored in the cost of power from your electric provider for running all theses equipment in a SOHO, not to include the cost of purchasing these devices and SW and HW maintenance including patching for security updates you can use a VPS that is designed for traders and all the above has been factored in. all VPS providers have an uptime on 99.9999 your VPS will be accessible 27x7 for automated trading and can be access securely with encryption theses days, which may cost less than having all that HW and spending your time maintaining HW instead of trading.
That topology reminds me of the 70's era computer tech school I attended. You may even be able to front run you're grandma if you get her a bit tipsy and have her trade from your LAN ... that is if you cheat a bit.
It's baffling why you wouldn't just use a vps unless you really really liked hacking together hardware. Latency aside it's just so much cheaper, you've always got the latest equipment, you don't have to deal with UPSs, backups take a half a second, your box will never unexpectedly die...Against pretty much no benefit of doing this at home unless you want to use the excess heat to help heat your house in the winter?