The Le Meridien is at the end of Orchard Rd while the Marriott is at the start. Shopping at Le Meridien is not as exclusive as around the area of Marriott.

If you want to go to the main shopping area where most of the shopping is (Ngee Ann City, Wisma etc), then Marriott is a better choice.

In terms of eating, there are plenty of food courts with cheap dining options everywhere so that's shouldn't be a problem.