I would say for the budget of under 2k I would go for a drz400e. its a little lighter than the 's' model and produces a little more power but has no passenger capability so no winkers or mirrors. I started out on one and it went everywhere you wanted without scaring the crap out of you. it was exceptionally good at finding traction where others couldnt- even the odd wr450
oil changes every blue moon unlike the ktm's, wr's and dare i say it my current bike.
just add petrol, check the tyre pressures and ride, then cover in wd40 before you put it to bed.
I do know of a tidy ccm404e (drz400e powered)with a 440 bigbore going cheap but it does need a head gasket and for a lot less than 2k
If going for a 2 smoke i'd consider the gasser 300. i believe its not as brutal as the orange one and a 300 will be a little less revvy on the road sections between lanes.
I used to ride a rm250 on a q reg down the lanes. it was fantastic fun until you had to do some road work. I had to ride from 50-60-50-60mph as it didnt like sitting at one speed and there is a danger of a light seize if you do but then this was a mx bike.
As for which is the best laner its down to wether your a setter or a follower
I myself now ride a v-twin injected '07 Aprilia rxv 450. a fantastic peice of kit and by far the nicest looking bike( well I think so and its not orange
). as for reliability no real issues except the odd oil leak which im on top of now and the occasional missfire on one cylinder in water but hey its got another to keep you going until it clears
awsome power but a little brutal on the slow bumpy stuff when finese is required. every time out I have a heart in mouth experience and occasionally a smudge where you dont wont one
but hey I love it.
thats my tupence