Options - not in any particular order:
--Moss kit per above - Lucas alternator - not sure if they have a good quality record or not.
--Hendrix wire wheel mounting kit with either:
-----GM alternator -or-
-----Denso alternator
--Dynamator alternator - looks just like stock Lucas generator, uses stock mount, pulley and fan - there have been some QC issues with these, so you'd want to have it checked by an auto electric shop before installing. See previous posts on these.
I like the Hendrix mounting kit with 35 amp Denso alternator - it's not as huge in your engine compartment as the Chevy alternator. These are widely used on forklifts and farm equipment and with careful online shopping can be had for $65 or so.
PS - if you have the opportunity to buy a 1-wire hotrod alternator, DON'T DO IT. It won't run your no-charge lamp. There's lots of discussion online about the pros and cons of 1-wire alts.
See my paper on the Denso conversion:
https://www.healey6.com/Technical/Alternator1.pdf