I thought your "rattles" over bumps was an excellent description.
I just bought an 850 which does the same thing. I didn't realize how bad things were until I drove my Mom's V70... major difference.

I remember a Saab 900 I had with the same symptoms... I replaced the shocks and struts, but the ride felt the same.

From reading this board, it seems that other things contribute to this feeling that you and I want to remedy... such as the mounts, the spring seats, sway bar links, control arms, etc. Each of these things have rubber components which deteriorate over time.

So I now believe that the shocks and struts were not necessarily the problem.. at least not the whole problem... on my Saab, and I have to assume the same is the case with my 850. I don't know how to tell what feel indicates which part needs replacing, and if someone here can better explain it, please do.
I do know the ball joint / tie rod test. But to tell if the sway bar link is poor compared to the spring seat, etc. loses me.

I am in the same boat as you, and fear that to get the ride I desire, I will just about have to replace everything. I am not really interested in spending that much, but at least with careful shopping, I can replace the brake discs, pads, rear shocks, rear springs, rear mounts, front struts, front springs, front mounts, front spring seats, front control arms and front tie rod ends all for about $1,300ish - give or take depending on which parts are OEM, and which are the Scan Techs (STs being about half the cost, but having only half the life, if that).


I can tell you that for most of these suspension related things, you will get your best pricing through FCP Groton. Even if you desire Volvo OEM, and it is not listed on their website, call and talk to Nick. I just about guaranty you will not find it cheaper. The only things I found cheaper were at Newandusedvolvoparts.com, where the Touring (sometimes called Economy) class Bilsteins were only $77 each with free shipping. Other than that, FCP Groton is your one stop shop for suspension. For Brake discs, eEuroparts has best pricing when you factor in the free shipping on these heavy items, and RockAuto has the best pricing for Raybestos Ceramic pads.

Cheers
--
1995 850T Wagon 101k
1998 V70 GLT Wagon 85k