@w2lie Phil is awesome. Reach out to him if you are seriously considering a G4. I believe he also has good holiday promotions going on.
People will also say Ray's Pager Sales. Nothing against them, from what I understand it's a very reputable dealership also. Nice to have options.
As far as SDS vs Unication I will repeat what I have said before.
If I only care about listening to one system, Unication G4 all day. If I want flexibility, SDS. Will the G4 out perform the SDS? Yes, but really it's only going to be in fringe areas.
The SDS was built for scanning - you have tools like discovery, can listen to more than one band, etc. For that it works great.
If you only listen to one system for 90% or so of your listening, the G4 is tough to beat with form factor, battery, and features while monitoring a single system. Yes I get they are working on multi-system, but so far the results have been sort of meh and multi-system scanning regardless of Unication, SDS, or even a top-teir Motorola APX is a meh experience as it is since you can't really stay parked on two control channels at the same time.