It is but because I need to travel approx. 6 weeks after the ceremony, I'm trying to avoid any unnecessary delays, even if they end up costing me a little more.That's plenty! It's an excuse to buy them a coffee, and cheaper than a notary.
Another thing: I think most people are kind of honoured to be guarantor/reference for people they know, esp if friends.
Normally I wouldn't be too fussed but it's just a timing thing on this occasion really.