The EX250 is a lot of fun to ride (both on the street and track). But at 6' tall I found the seat to be too low on the street. With knees high it rotated my butt back so I was sitting on the points of the pelvis, which led to the dreaded squirming after about 20 minutes. If I'd kept it on the street I planned to try and reupholster the seat to make it about 3-4" taller so I'd be less "knees high - bottom low" on it.
Other than that if you could pick up that 2005 for $1300 that would probably be a good deal for you. The EX is plenty fast enough as a solo bike to keep up with traffic.
I had the thought earlier today that I probably should have asked you for your definition of trail riding before offering my opinion. If you were talking about packed/smooth/dry dirt roads, then most any street bike should do fine there even with street tires. Once conditions get much more technical than that you'll need to ratchet up the "dirt" capabilities, and keep ratcheting upwards as the trail gets more rugged. Light weight and good ground clearance will get you in and out of places (even with a mild 100cc engine) that you aren't going to want to get into with a bike designed as a "pure" street bike. Sure, people used to ride their 500/650 Triumphs in the dirt, but once the lightweight 2T bikes showed up there was many a big bike that was humbled by a trailbike.
Don't take anything offroad that you can't drag back up out of a ditch to the trail you used to be on.
Or something that is so heavy you can't drag yourself out from under it without help (been almost there, I don't recommend it).
cheers,
Michael