Oooh, what a great present!
How much do you have to invest in this, if that's not too indelicate a question? If the veg garden is going to be very posh and ornamental, Harrod Horticultural do some really great beds. Ideally, you want pressure-treated timber, because it's just so much more resistant to rot and will last so much longer. If you're working on a budget (like me!) then you can buy gravel board at B&Q that is pressure treated. It comes in 3 metre (£7) and 2.4 metre (£5, but currently £4 if you buy 5 or more) lengths, and if you saw the 2.4 metre in half, you basically have a bed that's an ideal size - 3 x 1.2 metres for £18. It's not so wide that you can't reach into the middle, but there's length to ensure a proper crop. You just screw the sections together with long screws (Aldi £2) and you can add corner reinforcers (Aldi £2) for extra strength if you want. Once you've got the hang, it takes literally just a few minutes for the two of you to get one together!
Other ideas - you can get raspberries, strawberries and currants for the garden and plant them in ready for next season! (This is nice because it feels like you actually have stuff growing, not just a structure). Also, bare root fruit trees. Again, if you are on a budget, Aldi do the trees and currants very cheap (£3 for a tree, £2 for a fruit bush). It may be cheaper, however, to buy raspberry canes from an online retailer - Kings Seeds are inexpensive, but tend to be in larger lots, Thompson and Morgan are more expensive but I think they do an 'all season' collection which takes you from the first fruiters right into the autumn.