Do reel to reel tape recorders require much service?

As with any mechanical device, they should be serviced from time to time and especially if they have been sitting idle for years but generally speaking, they are very reliable. Routine maintenance should include cleaning the heads with a Q-tip and special head cleaners that are alcohol based as well as de-magnetizing the heads with a device that is specific to that purpose. This should be done every 10 to 20 hours of use.

What is the best blank reel to reel tape available today?

Recording the masters (RTM) are currently the best tape to buy as it is extremely high-quality and can be recorded at higher signal levels (hotter) than previously made tape formulations.