I went to both places back in 2007 and Fruita is right by Grand Junction so definately worth a trip there. It's got lots of trails from the car park area and varying dificulties. It used to be you could ride them up or down so if that hasn't changed then beware.
Fruita Trails we loved included Joes Ridge, Zipperty Do Dah and kesslers Way, the latter we did multiple times including 'one last go' just so we could say we crawled on to the return flight knowing we'd maxed our time out there.
Grand junction food wise is (was) a bit rank bar the micro breweries which have a restaruant attached to them and there is (was) a really good deli place we found that did fresh smoothies / scrambled egg bagels for breakfast as Dennys etc make Little Chef's seem like health emporiums! Moab is way better for proper food aswell as bike shops for those downtime moments.
Moab trails we loved were Porcupine Rim but see if you can get an uplift further up as it joins Kokopelli trail thats supposed to be stunning views thats higher up. Slickrock is great but only a couple of three hours fun really and gets packed at weekends so avoid then plus use old tyres on there as it eats rubber literally. Moab Rim, & Western Rim trail. All good fun!
It's not 'that' cheap either compared to UK, go armed with costs of items you want to buy and then compare but buy on credit card so insured too
Hope that helps