It's your call. You could spend hours messing with pressure/line length, or you could just go with the longer lines and not have to stress about it. There is no way you are going to get everyone to agree on a specific line length or pressure. I base my 10' line length on about a dozen forum members who have been kegging longer than I have and recommended 10' lines when I was was having foaming issues. Beverage tubing is dirt cheap at Home Depot/Lowe's and once you get things figured out, you can invest in the spendier stuff if you want.