Edinburgh makes no sense, sky high rates, expensive staff. But then, handy for lobbying/enticing govt should indy ref 3/4/5/6 etc. produce the desired result (desired by the SNP, not me…).
Dundee makes more sense, already has lots of call centres, so a wealth of pre-trained staff, cheapest purchase/rental/rates for business in any major city in Scotland. Loads of tech companies setting up there too.
The available transport links pay no part, it is a help/admin/call centre, not a manufacturing/distribution hub. The main costs will be staff salaries followed by business premises and rates.
In life, it's not who you know that's important, it's how your wife found out.