Asterisk extensions.conf modified to handle basic ivr/grps

We need our [login to view URL] file updated to play a Greeting (.mp3 file already prepared), to play an IVR menu (.mp3 file already prepared), and determine when to play our off hours message(.mp3 file already prepared). The ivr menu should accept any working extension as well as route to call groups they you will need to set up from the main IVR menu choices. The groups should be configured to allow a mix of SIP extensions and or external sip numbers ( Ex:Dial(SIP/15555555555&SIP/350,25) ). A defined voicemail extension should pick up on groups after a defined amount of time. Our budget is $50. Thank you.