I know you said you weren't wanting to blow a bunch of money but you could make coils for the rear for not a whole lot honestly. You could make them yourself for under 200 bucks.

Springs are roughly 40 a pop. $80
Sleeves are about 20 a pop. $40
Adjuster nuts are about 10 a pop. $20
Top hats are about 10 a pop. $20

Reuse your AGX's and mounts.

So roughly 160 bucks plus tax and shipping. Should still be right at 200 or less.

Just some food for thought.