To have timing chain, tensioner and rails replaced at a shop, was $800-$1200 at Florida labor rates. A big job to remove everything in the way, then replace. Over one working day, I would expect.
Water pump is not too difficult, but still time and money. Why do you think that you need one? I do not often hear of them going bad. I think the pump itself is at least a couple of hundred bucks and maybe 4 hours labor? Removing all the belts, fan and then refilling the system.
I would be concerned over the antifreeze from the tailpipe. You are looking at an aluminum block and heads in this engine! While the 5.6l V-8 is reliable and a long lasting engine, nothing can insure against misuse or abuse. Maybe it was overheated, and warped the head or block?
Have you gotten a mechanic to check it out yet? This is your best bet! Worth every cent you spend. A compression check of the cylinders will reveal a lot.
Good luck, and let everyone know what happens!
1989 560SEL (172k)
1989 325IC (122K)
2004 Suzuki Volusia LE (3500 miles)
2005 Yamaha Road Star (20 K miles)