Can i use an old(er) verizon or unlocked phone/pda/blackberry on verizon?

Hi, recently my blackberry curve 8330 from verizon has passed, i got the red battery icon with a diagonal cross through it. my manufacture warranty of 1 year from RIM is up, i have a two year contract and 8 months left until upgrade time in august. i could get it replaced but my parents dont like the data plan and we were never told of the 30 a month for data, so my mom doesnt want me to get a blackberry, but the other day my moms friend told her of his friend who works at verizon and was able to get rid of his data plan and ended up slimming his bill down. so i left a message and we havent got a phone call back, and i been looking at other phones in case i get something else and i was interested in the palme treo 650 or 700p/w the w is windows mobile and the p is palm os, i think i like the palm os since it was made by the phone manufacturer. also i know these phones are a couple years older and verizon nor palm makes the any more, i found some on ebay for 70 to 80$. so would i be able to drop the blackberry in lieu of either one of these. i made sure on ebay i looked for verizon or unlocked and new on mint conditioned with manuals. also they make wifi adapters for these so i can use it at home with my slingbox and sutch. so would it work, if so what do u recommend treo 650 treo 700w or treo 700p