Dont worry about age, I have a hoyt excell I built in 1986 and it has yet to fail me. I shot three hogs and one deer with it last year. This year I have used my newer bows, but the old excell still gets shot. I have gotten many bows/parts from ebay. The only problem I find with ebay, other than its normal inherent problems, is that when picking a bow, its a guess as to whether the bow will be a good fit. The bow you got is a fine bow, but if you are not familure with fitting a bow, or tuning it, id head to the pro shop to get some help setting it up for you. Id for sure get a new string and cable, if it has not had a new one put on in the last year or two, which it probably hasnt. There is a guy on ebay that makes great stings and cables for 45.00 bucks. I cant think of his name, but he makes the strings for the Womens US team. Ive had him make all my stings and cables for years.
As far as targets go, with field points, use a bag target. Will last for a LONG time. Broadheads, I would get a yellow jacket. I bought a new block 4x4 pro, and it isn't holding up well. Plus they are twice as much as the yellow jacket.
Good suggestion on targets. I dont go expensive because I have found they all wear out about the same. The block hold up well, but I wouldnt say a whole lot more than the yellow jacket.
Good luck
Burnie