Just get the BDS basic kit, and then work up as you get the fundage. Like I mentioned in another post the drop down brackets by BDS are very beefy and you may be very satisfied with those and will never buy the extended arms.
If you ever feel the need to get that extra inch of flex then you can talk to Dustin, NOBS, David, or any other qualified welder to make you a custom set.
Also you can use add-a-leafs in teh meantime while you save up for replacement leafs, or you can just get the parts from teh junk yard to do a shackle flip and then you wouldnt need full leafs.
The option are out there and yes you can do it for under a thousand (not including rims and tires) you just have to start somewhere.