i'll echo what most folks have already said, and maybe add a thing or two ...
for a 28" draw length, yes you do want 68" or more of hill bow length. 68" will be fine, 70" will be smoother still but that added 2" will be noticed.
like dick and others, i've grown up with hill longbows and have had dozens of them over the decades. except for the bow's length with regards to yer draw length, everything else is subjective ...
the new and vastly improved craig hill locator handle is what i'd recommend - much more positive a feel for either the 'death grip' or the 'single pressure point grip'.
the slight amount of string follow that craig induces is, imho, a very very good thing that adds a measure of stability without a noticeable degradation of performance at hunting distances. consider that as well.
i'm convinced that boo limb cores are just plain smoother than any other limb cores. make that uber heat tempered 'caramelized' boo, too.
glass color is way subjective. i like to see the pretty limb veneers, so clear is my first choice. second is black, third is chocolate.
i prefer the look of natural limb tips, rather than limb tip overlays. both can handle hmpe bowstrings.
i've had every model of craig hill. i think that less is good, sometimes. the all boo tembo, with only three lams, means less glue lines and perhaps a more efficient limb set. i'll put my 3 lam 54# tembo up against any like-weight 5 lam wesley. :D
take this to the bank - your bow with arrive at least 3# heavier than the labelled holding weight - maybe as much as 5-6# heavier. if you want 55#, order at least 53# ... and hope it won't be 57#. i thought i was slick by ordering a 47@28 70" tembo and hoping for 50@29 - it's 54@29 - i'm not the only one to report this happening. next time i get craig to build me a bow, i'm sending him my easton digital bow scale to use. i'm serious!
and lastly, at yer tender young age, are you SURE you want a 55# holding weight longbow?
PS - you should have posted this on the big HH bug thread.