personally i feel that amp selection here is OK... but very little variety where cabs are concerned.
as a markbass user i would recommend markbass. good tone and high quality stuff. although i must admit hartkes are very good value
for a head unit alone, you can get a little mark II from davis for $900. the other markbass amps that davis has will probably bust your budget. the little mark range will be around 1k or less. the LMII is discontinued and i don't know how much the LMIII will sell for here. you will have to rely on davis for markbass because the voltage on their amps is not switchable, so you can't order them from the states.
honestly speaking i am very keen on trying a genz benz but i'd have to order it from the states, and shipping will kill.
and then for cabs, you can get a solid hartke 2x10 cab for under $300. you could oso go for say markbass or EBS, but those cabs will be way way more expensive. remember that amps put out different power depending on the load. bigger cabs will put out more power, but most cabs are rated at 8 ohms, while most amps put out full power at 4.
using hartkes as an example, your amp would be most powerful when 2 8ohm cabs are connected to it. be it 2 2x10s or 2 4x10s, the power output will be the same. no doubt 2 4x10s are more efficient and hence louder, but the combined power would be much higher than whatever your amp is likely to be able to put out at that load.
you could get a pretty decent amp+cab combo within a 1k budget with hartke. or you could go for more boutique options in the 2nd hand market. now, if only someone was selling a used markbass...