Shopping eBay for the right rig

[kmac]

I've gathered that the machines cited below will serve my needs and now I'm shopping eBay. What specs would you look for in a Dell Optiplex SFF or a HP Elitedesk SFF if you wanted to build a robust but inexpensive high rez, four camera, BI based system for a small cabin that you would be monitoring remotely? Would they be something like this:

HP 800 G1 EliteDesk 800G1 DM Business PC i5-4590T 2.0GHz 4GB 500GB Win 7 Pro 64
or perhaps this
Dell Optiplex 7010 SFF Core i5-3470 3.20Ghz Quad Core 500GB, 8GB, Win7 Ultimate
or maybe better this?
Dell OptiPlex 3040 SFF Core i5-6500 6th Gen 8GB 500GB Win10 PRO DVD RW desktop

What would your "ideal for the need" machine look like? Low wattage is a plus and you'd want to swap out the HD for a WD Purple, wouldn't you?
What version of Windows would you want if you had never built such a system and were hoping to avoid tearing your hair out (I've read that there are differing opinions about versions of the Win OS in this regard)?

I will gladly provide further details about the functionality of the system I'm asking you to opin on the guts of (i.e., the kind of imagery I'm hoping to capture and the placement of the cameras). Appreciation in advance for those willing to throw down their 2 cents. I'm sure they'll help me and others just getting started.

Thanks,
kmac

 

[fenderman]

buy a unit that houses at least one 3.5 drive and one 2.5 drive...the listed wattage is max, its irrelevant. Even the i7-6700 skylake machines idle at 12-15w...dont buy third gen....buy skylake, also note that intel hd on skylake supports h.265 which may be useful in the future

 

[kmac]

Is there a model of the Optiplex or the Elitedesk in a SFF that has a 3.5 drive and a 2.5 drive or should I just be looking for a minitower?

 

[FrankOceanXray]

https://computers.woot.com/offers/hp-6300-pro-intel-i5-12gb-ddr3-desktop-3?ref=w_cnt_bs_95

 

[fenderman]

https://computers.woot.com/offers/hp-6300-pro-intel-i5-12gb-ddr3-desktop-3?ref=w_cnt_bs_95

That is a way overpriced 3rd gen unit...you can buy haswell or skylake for a few dollars more.

 

[PSPCommOp]

Is there a model of the Optiplex or the Elitedesk in a SFF that has a 3.5 drive and a 2.5 drive or should I just be looking for a minitower?

I'd recommend mini tower, I have a SFF and I wish I went larger. I have my HDD mounted but its extremely close quarters and I haven't had luck finding an appropriate caddy to hold the SSD. Currently I have it just resting in the open bay slot since it didn't come with an optical drive. If yours does come with an optical drive, you'd have to remove it in the SFF model to make the SSD fit.