Lempart Flex is a travel eSIM with unlimited data where, on some destinations, you choose the country your IP comes from. Where a US IP is sold, the destination page has a "Choose your IP" menu after the trip lengths: pick "United States" and you see only the plans whose IP exit is the United States, with their speeds and prices. You see it before you pay.
Angola · Bermuda · British Virgin Islands · Cameroon · Canada · Central African Republic · Costa Rica · Curaçao · El Salvador · Eswatini · Greenland · Guinea · Guinea-Bissau · Guyana · Honduras · Jamaica · Kosovo · Liberia · Libya · Mali · Mozambique · Nicaragua · Paraguay · Peru · Puerto Rico · South Sudan · Suriname · Togo · Trinidad & Tobago · Turks & Caicos Islands · United States
In the United States, "Choose your IP" lists each IP exit with its lowest price, the United States among them.
A US IP changes where your connection appears to come from. Each app or bank still makes its own decisions about access.
Sometimes. "Choose your IP" shows each IP exit's lowest price, and each plan shows its own price before you pay, so you choose.