I agree with 2many.
The OME is really, really nice. I was debating all about springs for mine (since I'm also on the continual budget), but after putting the OME 2.5" on my Dad's FJ-40, there's no other products I'll consider. That's how impressed with the Dakar's I am.
You could take it to a spring shop and have them either re-arch your existing springs, or make some new ones, but you'll be pretty danged close to the cost of OME anyway. If you wanted to save coin on the OME, you could probably pick up just the springs and bushings from them. Then when you get the cash in your hands down the road you could add the shocks. The spring pins and/or shackles you'd only need if your are worn, wimpy or wrong.
Dan