Frigidaire makes a nice little A/C unit which is only 12"X13"X16". it works well and costs very little.
None of the small A/C units available is repairable or even rechargeable.
Let's just call them disposable.
I have used other brands , but none smaller.
Haier makes a nice little A/C with the controls at the top front which works well in some applications.
WalMart has a 5000btu A/C with remote control for $129.
Bottom line is to find one which physically fits your application and has the controls and vents located to ease installation.