In Tbilisi, there is a company which is renting out camping and hiking equipment for the very affordable prices.
Here are their contacts:
Adress - Giorgi Saakadze Square, underground pass N11
Tel: +995593761651, +995551542249
Working hours: Every day 11:00-20:00
Web: http://www.tent.ge/ (although website is in Georgian youstill can check out some products and/or give them a call).