Don't get caught up in the design, although it's good to understand the differences and all that. It's not going to make or break a cruising boat. Too many opinions about what is 'best'...
For a good liveaboard
cruising boat, small enough to singlehand, but large enough to live in relative comfort, I'd be looking at 32-34 footers. Boats like the Pearson
323 or Bayfield 32 are really excellent choices.
If your convinced on living in a 30 footer, you can't go wrong with a Tartan 30
Bluewater proven, excellent sailing abilities, well built, and roomy enough for a 30 footer (aft galley
layout only!) The only
other 30 footer I'd want to own is an Alberg 30
. Very different designs, but the Alberg
30 has the best interior
layout you're going to find on a 30 footer, and it's definitly a bluewater boat. Both are very simple boats and require upgrading to achieve liveaboard/cruising comfort and self sufficiency.
You can get a good T30 for around $10k and a good Alberg
30 for about the same or maybe a little more (lots of bad ones out there so shop around!)
But if you can spare a few extra boatbucks, take a look at a slightly bigger boat. 32 foot seems to be the sweetspot for my own personal comfort level, but everybody is different... I'm happy with my 30 footer, but there are days when I'd like a better galley
or a bigger berth... And when it comes to cruising, you'll appreciate the extra tankage and storage
space. The extra 2 feet will be unoticable when sailing, except you might get an extra knot
of speed out of it