Honestly, if you've never built a gundam model before, you may want to get something slightly simpler than these two. While PGs aren't hard they do have a ton of parts, and may daunt you. On the other hand, the light up model will involve some simple electronics (nothing too complex though), but not nearly as many parts. If you've got the cash, get both. If you like the designs, you could just get the 1:100 versions of these kits and build those.
And yes, the PG Wing zero is that big... I don't have one personally, but I've seen it.