DIY fermentation chamber from scratch

I'm looking for some advice on a DIY fermentation chamber. I don't have anything at this point so I was wondering what you guys have found to be the best/most cost effective method. For starters, unit will be in my garage with hot summers of 95+ f and mild winters rarely below 30 f. Also this will be primarily used for fermenting around 68 f. I would like the opportunity to convert it to something with a tap that i could serve from. It needs to be big enough for atleast 2 glass carboys.

So, I've seem people make these out of mini-fridges, chest freezers, and window air conditioners. Would a portable airconditioner unit work? I havent seen any of these and im not sure why. What do you guys think is best? I don't want to spend $30 on a mini fridge and have to spend 120 on conversion materials when I can just spend a little more on converting a chest freezer.

Free stand up freezer from craiglist and eBay controller.

+1 on the free stand up feezer. I couldn't find one, went with cheap chest freezer and love it.

Definitely anything free would be ideal. I'm worried that a stand up freezer wouldnt have enough floor space for what I'm looking for. I think I would have to build shelving in something like that. Thoughts?

I can fit 2 6.5 carboys side by side in mine.

Why a freezer and not a fridge? defrost is nice to have, no? A decent sized cheap fridge w/ dual temp control and small heat sourse should work well IMO.

I cold crash in my freezer at 0c. A fridge would work fine too, not sure it would get to 0c but I'd imagine as long as you bypass the thermostat it'll get there eventually.

Usually when I have multiple options like this I just pick up the one that's free, lol.

The nice thing about using a stand up freezer is I put my carboys on buckets, which means I don't have to take them out of the freezer till after I siphon into keg. If its a fridge/freezer or chest freezer that wouldn't be possible. Bad back, try not to lift so much.

I built a ferm chamber with a free mini fridge. I could probably get 3-4 carboys in there and I still spent enough I could have bought a chest freezer. An upright would be awesome but chest freezers are cheaper. If I get one for fermentation I would get a CO2 transfer system so I wouldn't have to lift full carboys.