i cant say ive seen two buckets, a bench rear AND two jump seats.......
at least thats what it sounds like your describing....correct?

when you say bench....usually it means a seat that spans across the entire width of boat(seating area anyway) a few feet behind the front seats, all facing forward.  typically, whats in a daycruiser is two front buckets followed by a pair of cocktail seats with two small jump seats on both sides of engine cover.  the cocktail seats are right up against the front buckets and they face each other.  the jump seats are near transom, on both sides of engine cover and face forward, same as front buckets.  is this what youre after?  if so...i think i just read a post about a resto, which included round back buckets...but he made a rear bench, instead of cocktail and jump seats.   if i find the post, ill put in a link for ya.

also, keep an eye out in the classifieds....some people sell full interiors...for day cruisers as well as smaller boats.  could be a good place to start and would definitely be cheaper than having the frames you make upholstered .....just food for thought.  post some pics of your boat, we'd like to see

i hear ya on the shipping.  it can get outta hand.  the pic you posted has the cocktail seating arrangement.  some boats/seats have a little more room between engine cover and cocktail seats.  guess that could be up to you as youre making them from scratch.  they typically seat 6-8 people.  cocktail seats may seat two people per side.
your hustler looks very much like my tahiti AND many other daycruisers.  spectra 20, eliminator, bahner, hawaiian, etc.  the pic you posted is of a southwind.   companies of the era copied each others designs, changing very little to call it their own, or nothing at all.
i might be able to get you some pics of my interior, looks very much like that in your pic, maybe some rough measurements....but final size will be up to you in your boat.  as it is now, i have more room between engine cover and seats....they dont touch....you can actually walk thru. its tight, but you dont have hop over seat.
while youre seats are out, have you checked the floor for soft spots?  soft floor could mean some water damage....which if water intrusion was bad enough, could get into your stringers....which is a bit of work to repair/replace.  think of the stringers as the frame of your boat and if they are weak/broken....the rest of hull is free to flex too much...bad news bears.  stringers are hard to check without removing floor.  so if floors are bad/soft, id remove it....then check stringers.  it is possible to have bad floor and good stringers...  you can search on here for stringer or floor replacement.  should be quite a few who have done it here.  a strong floor helps your boat a lot.  will make it feel more rigid and confident.

im in the same boat......   haha.

as far as ideas....all ive seen are two buckets....middle seat are cocktail style or back against the buckets as you said and rear jump seats or a bench.  lots of people who redo their seating....go with two buckets and a bench with engine doghouse the full width of boat, no jump seat.  aside from that configuration comes styling of individual seats...meaning round back versus cornered or straight.
do your homework on stringer repair/replacement...as it can have a negative effect on how she handles if done incorrectly.  also, make sure glass isnt damaged from that impact on rear corner. 
let me see what i can do for you as far as pics go.