Well Tench generally are bottom feeders but that doesn't mean that you'll neccessarily be ledgering. Some of the best tench that I have caught have been on the float, laying on in 6-8ft of water. Tench can be and often are good fighters, once hooked they tend to give a steady if not consistant fight often refusing to come to the net and often heading for the nearest obstacle such as lillies or weeds.
What you need is a rod about 12ft in length and with a medium test curve of around 1lb in weight. This will give you the ability to hold a decent fish whilst maintaining control.
If you are just starting out, one rod that I can recommend that will not break the bank is the Daiwa Super Sensor Z Match which is more than capable of meeting your needs.