You cannot go wrong with USAK. If you could spring for a semi-trad, it will dress up a bit more nicely than the casual. I have both, and love them both.

The difference I notice when wearing the casual, is that it lacks the reverse pleat on my right.

The semi-trad is built much like a traditional kilt---deep pleat to the left of the apron, reverse pleat to the right---with shallower pleats. It moves just like a trad kilt. Being about a 5-yard kilt, it does not need the internal construction of an 8 yard kilt (pleats cut out, steeking, interfacing).

With respect to any package, weigh the use you'd get out of the components versus the savings of buying them together. The current special on the casual package is pretty attractive! I might upgrade the sporran to the Rob Roy: that is a very nice one & may have a tad more room.

Choice of tartan: I'd consider Rocky's own American Heritage tartan, which is absolutly gorgeous. You might like his German Heritage, if your people are from the "Dutch Fork." Isle of Skye is always nice, or Caledonia is a classic red/green dating at least to the early 19th century.

I have a well-loved tank, but this USAK semi-trad the kilt I wear most often:

usak-pleats-s by arcturus1997, on Flickr