Rigoli wouldn't care about turbo lag, as he runs a drag car. Top end power will have no difference between one big turbo or two smaller.

Twin turbos appropriately sized result in less lag. Two big turbos would probably be a mistake.

If you run twin turbos, you go with smaller turbos and get better low-speed response ('cause they are smaller), AND more flow ('cause there are two of them). If you make a really clever piping system with butterfly valve you could have dual-path intake (short and long) to improve it further.

Far easier and probably more reliable to use a single. But if you do your own work ... might be a fun project.