I manage a tire shop and deal with this every day. First step is to get the wheels/tires on a balancer. idealy it would be a road force balancer. it will cost extra to have your tires road force balanced but this will certainly reveal ANY vibration due to imbalance, out of round, or otherwise mismatched wheel/tire combos. not all tire shops have this equipment so it may take some searching.
as for the front end having worn out parts; you should be able to get whoever is doing the balancing to check your front end for free. they should also be willing to show you what is bad and what is good.
the alignment is a whole other story. the alignment itself WILL NOT cause your vibration. do not let anyone ever convince you otherwise. worn out parts/tires and out of round/balance wheels/tires will cause your vibration. my guess is they are simply out of balance.
My advice to most of the guys on this board is to find an educated and experienced tech that works on a variety of vehicles to take your car to. These cars aren't ferarri's or anything "exotic." They are unique and can present their own unique problems. I'm not saying that you need to have your "guy" fix everything for your or not be involved in the process, I just can't stress the value of an honest professional opinion and inspection.
You can choose to either invest a lot of time and money into tools and parts and try to fix things yourself - the learning curve can often be steep and expensive or you can save yourself a bundle and hire some help.
Hope this helps,
Ray
