You are considering two amps that cost around £400 and then adding a Beresford (£150 - £200 depending on model).
This implies you can afford up to about £600 which will easily get you a good used Naim Nait 5
i (italic version) with about £100 of change left over for cables etc.
Your Squeezbox 3 already contains a DAC so just plug it in to the amp with an RCA lead.
The Nait 5
i (italic) has a front panel mounted 3.5mm socket for your iPod. (Get a
Russ Andrews GQ24 0.5m jack connector lead for £29).
The Nait will do a fine job with the Leema Xeros.