Softest Shocks on Budget - Cheap Alloys with 3.5" Backspacing?

My shocks need replacing, but I'm not sure how long I'll have this truck so I don't need the highest quality shock money can buy. I do however, need something really soft. I spend about 70% of my time on washboard forest roads, and the current shocks (dead or not) are rattling my teeth out.

No lift on my stock 98 SR5 4x4.

Also, I'm thinking about moving from my stock 235/75R15 on steelies to pizza cutters of 215/85R16, but I'd want to shed some weight in the process. Are there any cheap alloy 16x7 wheels with 3.5" backspacing? I'd really prefer not to install wheel adapters, but if it means getting a cheap set of stock alloys for $100 and wheel adapters to push them out 1.5" for another $150, I may go that route.