A number of folks on the Jeanneau owners forum sail there 29+ boats from England to the main land, even from Finland/sweden etc too. My 85 Jeanneau Arcadia has an open water cert from that time frame. I would consider sailing across open water for a day or two. Not sure I would want to do an Atlantic or pacific........but with proper planning etc, it could be done.
Also, this BS about full keels are the only ocean going boats.......just that BS. Look at the new HR's, Oysters. Swans etc, ALL are partial or fin keels. Also for the given length, will be faster due to the less wt of the boat. Along wth the ability to out run to a degree a storm. Altho at 30', the likely hood is slim. Now if talking an open 60 vs a full keel 60' boat, no issues. as open 60's can hit 20+ knots vs a full keel max is about 9-10.
Jeanneau Attalia's is a 32' boat from the 80's, very plentiful in Europe. I recall seeing prices in the upper teen to low 20K euro. From a quick exchange rate in my brain, a bit more money, but overall, still probably less than a boat from here.
The Ben oceanus, altho not my personal favorite, will do what you want. the First series, like an older 28, 30 or 32 will do what you want. Many are raced in double.single hand ocean races such as the transquandra. There is a person upfitting an older Jeanneau SO33 for such a race, as IIRC the requirement was a 10m boat.
She drives me boat,
I drives me dinghy!