Setup Multi-Region Install by Store or Website

Question

We are building a Magento CE website with UK, EU and US regions for a single brand and less than 1000 products that may be available in some or all of the regions.

We want to avoid currency fluctuations so we will have separate EURO, GBP and DOLLAR bank accounts per region rather than converting from base currency at cart to region currency.

Is it best to setup our install with 3 separate "websites" under 1 magento installation? Each website to have a separate base currency and each using separate merchant ID so that there is no currency conversion needed per region from viewing/selecting/adding product to cart up to payment and forwarding of funds to relevant currency bank account.

Or is it an option to do this with 3 "Stores" under 1 "Website" under 1 magento installation using solution here?

This is more applicable to the Sagepay payment method we intend to use but we will also use paypal or stripe for payment.

Answer 1

From @Cags comments a formulated answer

If you want to manage prices without currency calculation go with separate websites, you can set the prices for each product/website.

The other choice is to go with global prices and let currency calculation do the magic.

So 3 websites and price per website setting. System / Configuration / Catalog / Price -> Catalog Price Scope => Website

Answer 2

Correct, three separate websites, except Global currency prices are display currency only, checkout is always in the base currency hence why you need the three websites. You do however need to maintain all the product prices individually per currency/website or have scripts that perform the updates for you.