Not sure where the travellor is going. The farther forward it is, the more purchases or larger winch
you are going to need to trim the sheet. We had a 4-1 purchase
on the traveller mounted on the bridge deck
of our W32 and had to run the sheet forward and back to a winch
on the cabin
top to have enough power to sheet in the sail.
Garhauer makes an 6-1 two speed block system that should let you get by without a winch if you have easy access to where the sheets
exit the blocks on the traveller. Garhauer Marine Hardware -6810645
Believe Ronstan makes an 8-1 two speed setup and probably Harken
as well but they are quite spendy. I've got 6-1/3-1 end boom setup on my Pearson
35's 15' boom and it works well. Pull on both sheets
for rapid control like when jibing and 6-1 for power by pulling on just one sheet.