I am also working on a list and i got alot of advice from dakkadakka you could use
Annihilation barges are a necrons best friend
- you get an overlord on foot and a annihilation barge/command barge (easily swappable between the two) for only 33US$
- you get more speed and shooting power from the Annihilation barges
- you get 2 of them at 180 points (cheaper then a monolith)
- they can easily harrass any 11 armour vehicles (rhinos, razorbacks, trukks, etc..) someone said they average slightly higher then 1 pen and 1 glance a shooting phase
- the twin-linked tesla destructors will rip through horde armies
Also I would get rid of the lords and get Harbringers of destruction with eldritch lances and one with a solar pulse
this gives you more antitank shots and the solar pulse can help you get one more enemy turn of night fighting
Thats all I can think of for a more footslogging army, but i'd read around the forums for more information on necron tactics, thats where I found alot of mine