If you are looking for plans just search the forum for them, there are tons. I agree you best bet is to get a chest freezer, but with that being said I have made one out of a 1.7 cf dorm fridge and insulated it. Wasn't cheap, but I can get the temp down to low 40's for lagering sitting in a room that is about 65 (basement storage unit).
Double Dog Brewing
Keg 1- Schitzngiggle Oktoberfest
Keg 2- Flat Tire Amber Ale
Keg 3- Twisted Pumpkin Ale
Keg 4- A Night in Vegas APA
Bottled- Summer Saison, Bohemian Dunkel, Second Shot Irish Ale, The Kraken Barleywine
On Deck- Schwarzbier, Snooty Fox Brown Ale, HOP-Head IPA