If fuel economy is your goal, then a stock replacement cam would probably be best. Personally, I prefer hydraulic lifters. Much less maintenance. And the way I've cleaned the tops of pistons is with carb cleaner, a putty knife and lotsa elbow grease. Now if you're leaving the pistons in the holes while cleaning...well, I'd sure wanna run a shop vac around the edges just to make sure that no junk got down between the piston, cylinder wall and top ring.
hth,
