I can only advise on hardware I have experience with so, below is the parts needed.

Baogeng UV-5R

Raspberry Pi 3

16gb SD Card

DMK Engineering URI

DB25 Male Connector

2.5mm Male Speaker Jack

3.5mm Male Speaker Jack

Radio

The radio I decided to use on my Allstar node is a Baofeng UV-5R. There is a few reasons I decided to go with the Uv-5R. First and main reason: very simple modification to connect to DMK URI; they are priced very low like $15.00 for the body only and $29.00 for complete radio with charger. The second reason is you can find the UV-5R everywhere, eBay, Amazon, Banggood and I’m sure you can find more places. Third reason; there is a ton of information out there about the radio on the internet. So the Baofeng UV-5R is the one to get.

www.amazon.com/BaoFeng-UV-5R-Dual-Radio-Black/

Raspberry Pi 3 & SD Card

I went with the Raspberry Pi 3 because of the small size, low price, ease of use (I like Linux OS), and has built-in WiFi. Also the Hamvoip.org site has an image to install on the SD Card for the PI with all the documentation needed.

www.adafruit.com/product/3055

DMK Engineering URI

URI (USB Radio Interface) is designed for linking amateur radio communications through personal computer network channels. The reason I chose this interface is because; good documentation, $69.00 price and comes in a nice case that is labeled. Please note there are many other options out there but, I know this is a solid reliable choice.

http://dmkeng.com/URI_Order_Page.htm

DB25 Male Connector and 2.5mm 3.5mm Speaker Jacks

There isn’t much choices on the DB25 male connector, just make sure you order one that is designed to be soldered. The 2.5mm and 3.5mm speaker jacks also need to be able to solder wires. I suggest searching eBay and/or Amazon for the best price with shipping.