diy display fridge

Hello…i am trying to make a cheap option display fridge(delhi counter style) i have seen them new @ 1700 which is way out of my budget...i was wondering if i can mske my own...i have found somewhere that makes custom units of stainless steel and glass...perfect for what i need but with no refrigeration inside for 400
Can i take the internal guts from an old fridge and put it into the unit? OR can i put a standup air conditioner unit into it(i know this only goes down to about 16-17 degrees) …are there any problems i might encounter? Thanks.