Is there a program for windows that would let you use a hardware voip phone to talk on skype? (I don't want to spend the money on a hardware phone and then find out I have to buy a different one if I switch to a different VOIP service/asterisk)

What do you mean a hardware VOIP phone? If it has a USB port and drivers then it should be able to work with Skype. Currently I use a regular wireless phone and a Phone > USB box that I picked up cheaply. It made for a cheap wireless Skype phone.

I mean a hardware phone that would connect into an asterisk server over a network

I use the Vtech Wireless skype/land line phone

http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0665000FS10070651&catid=23014#

Jared555 what you need to be specifically looking for is a skype with SIP phone (multi-function). SIP being what you'd be using should you decide to connect with an asterisk (as SIP currently appears to be more widely supported with voip phones than IAX2 in alot of cases).

Many phones out there do support both (just keep in mind some of the preprogrammed skype ones might not, so keep your eyes focused on specs and tech sheets with the devices).

We are currently using a Cisco phone for our VOIP/Asterisk server. On skype, we just normally use a normal headset with microphone, and it turns out just fine with that set up anyway.

Is there a program for windows that would let you use a hardware voip phone to talk on skype? (I don't want to spend the money on a hardware phone and then find out I have to buy a different one if I switch to a different VOIP service/asterisk)
Can you explain are headphones and a microphone not good?

you can try skip2pbx

USRobotics Cordless Skype Dual Phone - Integrating seamlessly with the powerful Skype Internet voice application, the base station plugs into an available USB 1.1 or 2.0 port, and connects to your existing phone line.