I was wanting to make a self-watering system for my container flowers

there are drip irrigation kits available. If you need to coustomize....farmtech in iowa will get you what you need, I have got my veggies garden on drip irragation. I won't say the main line is skinny....but I run it between the plants and it's not so noticeable. Throw some mulch over it. The main line you puncture and set your drip control disk to it. From the control disk you a small diameter flexable tube to a watering stake. All of the above have handled the iowa winters just fine. The control disks come in different amounts I have 1/2 gallon emitters sooo over an hour...1/2 gallon of water per plant is used. If more water is needed by different plants... swich out the emitters.

Hardware stores carry drip watering systems like the one you described. :)

its a cost thing...how many kits for 125 plants?

http://www.instructables.com/id/How-to-make-a-self-watering-container/