I have a PIV and it is a very good park hunter. I think that it would do well with a small coil, but I have never used one on it. I have had a Vaquero and it was a super park hunter and will reach deeper than the PIV ever can. The PIV has some nice features, it is generally a nice machine. The Vaquero with a small coil is a scary, good deep machine and has amazing target separation but no TID per say. With time you will begin to understand what is under your coil to a great degree. You will dig more pull tabs with the V than you will with a TID machine but you will also get more rings and gold than if you ignore the tab readings.
The V is a very good relic and fresh water beach hunter, I never had it in the water though.
I now have a DeLeon and it is a very good park hunter. A friend of mine had one and was able to hit coins at the 10" mark. I haven't experienced that yet but for now I am running my sens quite low and at sens setting of 1 I have pulled out a coin from 6" with a solid TID. You can't go wrong with any of the suggestions that others have made here. There is a site http://thegoldenolde.com/oldego5.htm . More importantly you have to figure out what you want a machine to do for you and what you want to do for your targets. I had an XLT last year and didn't care for all of the menus, I was always worrying about what else I should be adjusting, it is a very good machine, just not for me.
Take care and good luck, and get digging with something for now.