Hp procurve 25XX series vs cisco devices

[platformt]

hello, i need a help with the next questions

i have a company enviroment with the many more cisco 35XX series switch, and cisco 2821 analog gateways, and cisco call manager 6.1 and IPCC 5 versions. of course this is not a complete system. the problem is that: the cisco support is very expensive in 1 year because i interesting the HP 25XX series switc and Hp analog gateways.
i have a next questions:

1. what is the observations the HP procurve 2500 series? /maybe versus cisco 35XX series?/
2. how many knows more or less as the cisco switch?
3. i want a buy a hp analog gateways, but i don't know which type is good. in this time i use the cisco 2821, so i need a

same knowledge in HP series
4. what bugs can "working" with this hybrid network devices? Cisco call manager, Cisco IPCC, Cisco secure acs with HP procurve

25XX series switch, HP analog gateway?


sorry my poor english language :)

Thanks the answers!

Thomas