You probably want to read a lot of the Kitchens forum on this site, then post your plans and questions there. Many of your questions have been discussed extensively there already, but you will find lots of folks willing to post specific helpful advice on your situation. Plan to post a drawing of your current and proposed layout to take best advantage of their expertise.

There is no nation wide best cabinets. Why? Cabinets are cost prohibitive to ship so majority are regionally built. It's unusual to buy cabinets more than a few hundred miles from site,50 is more like it around large population centers. Well I suppose Ikea is nation wide but best and knock down shouldn't be used in same sentence.