My lines are rather longer than yours 4.55 mi and 67dB downstream attenuation. I get 2600-2900k downstream and around 400-500k upstream. Modems that have been very successful for me are dlink dsl 320b-z1 (needs config tweaking for sanity as defaults are nutty when set up as a straight pppoe modem, and must not be used as a router as it is horrendous and unsafe in that case). The dlink modems are what I am using now. Pert of their high speed comes from the favtvthatbtheybseem ti run at a really really low downstream SNR margin compared to their target. An initial 6dB or 3dB downstream target soon drops down to 1dB or less at which point they start to become a little too aggressive and are pushing their luck. They are an ideal choice for me tho as I want extreme speed at all costs, and since I have three bonded dsl lines with very fast load-spreading and failover, then I don't care about a modem resyncing once a week or so as I never even notice it since the others just almost instantly take over as the ISP's routers (and my own) react having detected the failure within seconds.
I have recently very briefly tried a ZyXel VMG13120-B10A (see
http://forum.kitz.co.uk/index.php/topic,19011.msg338... ) which was extremely fast. Haven't got it properly set up yet. This device, used as a modem-only, not a router synced at 3100k instead of a typical 2700k (best ever 2900k) with the otherwise excellent DLinks. According to that article linked to and various other sageful opinions, the variant B10A has better hardware for long DSL lines than the B10D, but unfortunately I am told that the more desireable 10A model is becoming harder to get hold of. (Ebay?) I should have got two more units quick myself.