Don't know about the Alinco, but my 718 is great for digital with a Signalink interface. They all come with DSP now. I am a casual ham user, and the 718 is perfect for my needs. Very easy to use as well.

You may as well buy a new rig, as most hams think their used gear appreciates over time. I have bought used stuff on ebay, and what not. Everything worked as advertised, so I guess I am lucky. I just finally figured out it was better to just buy a new rig, and not pay out the ying yang for a twenty year old outdated rig. If you want a basic HF rig, then you can't go wrong with an Icom 718. Mine does everything I need, and I got it for under $650. 

Yup, lithium is the way to go. I use them in my kids toys, digital camera, and remote weather station. They easily outlast alkalines by miles. The extra cost is initially is negated in the end.