I have done considerable work in this area. Yes, it can be done, though there may be various regulatory requirements to be met.
Be alert to the fact that alternators with internal regulators (common to most cars etc.), are less well suited to aircraft. The reason is that there is much less circuit opportunity to include an over voltage system, to remove that alternator from the circuit, if a system failure takes it over voltage. This has happened to me, and will burn out a lot of expensive radios and bulbs, if they are on when it happens. It is a certainty that the pilot will not get these turned off after becoming aware of the overvoltage, before damage is done.
The are additional circuits, sometimes referred to as "crowbar" circuits, which can provide this protection. The saving in a compact simple alternator installation, can be lost if you melt some expensive radios. This is one reason that internaaly regulated alternators are not common in certified installations. I do agree though that the reliability of alternators and regulators is going up, and such failures are less common. Combined with the fact that modern avionics will often tolerate voltages up to 30 volts, the risk is reduced. Understand what the implications are before you take the simple route though...
Pilot DAR