i believe foundationless should be less expensive than foundationful. the rest of this post is for folks who don't have more money than they know what to do with.
if you have a table saw you can run your top bars thru at a 45 degree angle before assembly and get the frames pictured. save the scraps, they make perfect comb guides for 3/8"thick x 1 3/8" wide bars for your top bar hive, just glue and staple them underneath.
if you don't have a table saw select wedge top bars when you order frames. break off wedge and glue and staple with wedge facing down.
if you have grooved top bars get popcicle sticks (craft sticks at wally world) and glue them in the groove projecting down.
p.s. i would not of made this post if this was in the for sale section it's good info just the same.
all that is gold does not glitter