Looking for a reputable shop with reasonable prices and good equipment near airport or not too far away.

We travel light (small backpacks) so want to go straight there from airport.  

There is a stretch of shophouses, for about 500 meters, on the main road due south of the airport exit. 
 

if you walk around there and look around, or ask the locals on that road,  they should be able to recommend one or more rental places nearby. 
 

Opposite Tesco Lotus there is a small place run by Khun Chao who has bikes at a reasonable rate.