I went through big alternator problems with my TA last year and learned more than I ever want to know about them.
A generic 10SI from a local parts house will work for a basic car if you manage to get a good one. But I gave up after trying two of them and upgraded to a 94A 12SI Delco remanufactured alternator. According to the Delco tech site it has the most low RPM amps of any of the original-design early alternators. Problem solved, with overkill. And less than $100 purchased off the internet.
If you are really going to put a huge load on it then you will need to go with a later alternator or one of the aftermarket versions like a Powermaster. And also consider wiring upgrades as already mentioned.
I found this link very helpful:
http://www.acdelcotechconnect.com/html/tas_alt_12si.jsp