Newbie Suspension Question

Hello fellow taco lovers. I just recently bought a 2006 double cab trd off road. This is my 3rd tacoma I've owned, but my first 2nd gen Tacoma, so I feel like a newbie. I bought it off of a guy that only owned it for 6 months and barely drove it and didn't know anything about it. But, basically the struts and/or rear shocks are blown. When I hit a bump on the highway it bounces for the next 1/8th mile. A look under the truck reveals (4) leaf springs on top of a 2" rear block lift (which I'm not a big fan of block lifts). And I'm wondering if 4 leaf springs is stock or if someone added a leaf in addition to the block? The front coilovers don't look like anything special which leads me to believe they are stock, but the truck sits fairly level, so I'm confused. So I included a picture of a measurement of the front coil. The rear is only about 1/2" higher than the front. So I'm at a loss as to what to buy for this thing. I do like a stiff rear end for towing and hauling, so if 4 leaves are stock, I may take out the block and add a leaf. But i want to know what I already have before I buy anything. I think I want to go with bilstein 5100 adjustable struts in the front. But need to know what add a leaf and shock to buy for the rear. Pictures should help. Nothing on the current suspension is labeled to help me either. Let me know what you guys think. Also, I read online there was a recall on leaf springs on certain models in this year range. Are these old ones? New ones? Who knows.