Given the 3.5 Death Giant has a place in my heart, you had me open my MM3 instantly so I could see what's what. Also, check out the
Monsters as Races index for proper PC application.
Off the bat, the Death Giant really isn't PC friendly, given it has only one life...lest its companions are incredibly smart and fast should it die. And given that it would be in an Epic adventure (because of established HD and probable LA), it's going to be often. And speaking on its companions, they aren't really going to appreciate Frightful Keening, it's most powerful ability (other than Guardian Souls), or the chance of losing their soul when close to death while standing near one (or losing it period if slain). It's hard to be a team player with a Death Giant.
Outside of that, the powerful benefits of being a Death Giant are there, and just the Guardian Souls ability is enough to make your mouth water. But again, you would instantly be playing in an Epic adventure at the start, lest the DM with willing to work some magic. If it is indeed an Epic adventure, the necessity of LA is questionable, given PCs 23rd level and up can become fairly unbalanced. With Death Giant abilities having the potential to be that way as well, it's really DM call on this. Myself, I'd give very little LA if at all, but till I actually play through an Epic game...*shrug*