Well, if OPB hasn't worked out, then has been pointed out, there are two great boats currently for sale on Craigslist... the Scampi 30 and the Albin Cumulus.
If those are honestly out of your budget...and I totally understand how they could be, it's not the sales price that's the killer, it's the recurring costs... then there's a Cal 24 for $1800 on Craigslist. It's not glamorous, it's not fast but it can absolutely do the trip. Cal 20's have gone and the 24 is a lot bigger.
There's an old Columbia 26 for 500 lousy bucks on Craigslist.--
http://sfbay.craigslist.org/eby/boa/5959569234.html -- Again, not fast. --> Definitely not glamorous. But it will sail to Hawaii and not break the bank. BTW, I dunno about the bubble-top Col 26. ugh. But the oldie which is a stretched Col 24... they're pretty solid.
Until yesterday or something, there was a Bristol 27 on CL. The Bristol 27 was the boat that Carl Alberg designed for Bristol Yachts to compete directly with the Triton, which he also drew. They are solid as a rock cruising boats, if a bit top-heavy to my eye. Again, not "fast". Not "HOT". But solid and it will get you there.
The thing about really slow boats on the race to Hawaii is that they rate so much slower that you can finish DAYS behind the ultralights and beat 'em on handicap. It's happened before. Also, are you experienced enough and aggressive enough to drive an ultralight hard, day in and day out and get all the performance out of it, that you should? I'm not. I took a Santa Cruz 27 to Hawaii and I absolutely should have had a slower boat. I didn't have the spinnaker up all the time, I wasn't playing games with the squalls and so on. I just pointed the boat at Hawaii and kind of tried to make her keep going.
Are you aggressive enough and skilled enough to get everything out of an ultralight, all the way to Hawaii? If the answer is "no" then.......don't take an ultralight.
But honestly, that Scampi 30? The boat has a working diesel. It's a great design, they made about a bazillion of the mark iii's and they're still cruising all over the Baltic, not to mention probably 50+ on the East coast of the US. I've been beaten by Scampi 30's. This one has got some fancypants Ballenger double-spreader rig...so that's anice replacement, there, and I bet dollars to doughnuts that the running backs are for sail shape, not to keep the stick up.
Peter Norlin nailed it on that boat's design. Look at YouTube, there are umpty-ump Scampi 30 videos on there. The Scampi 30 has a big cabin and a dinky little cockpit. That's great for singlehanding and doublehanding, everything is within reach. Offshore, if you take a wave in the cockpit, you're not filling up a bumptillion gallons of water. There's a nice bridgedeck to put the traveler on...the primary winches are right there...it's a tiller boat. Sure it's an IOR boat with big headsails and a little main, but you don't HAVE to fly that 155% every time.
I dunno, man.... if you're on a budget, or just starting out, there are a couple of awfully good options available on CL right now.