Some thoughts in no particular order
Overall cost - your build sheet is showing almost $2500 for the intake, head, and cams, and doesn't include the various gaskets, fasteners and the like. It seems to me that selling the 2.0 and dropping in a 2.3 would have a total cost of less than half of that - plus it's a lot less work.
If you go with the 2.0 - please take note of the following:
1) The only legal 2.0 head/intake are the FRRP head and Cosworth intake. We expect F2 to be submitting information to homologate the head and perhaps the intake, but haven't seen anything from them yet. Don't have enough knowledge regarding relative performance advantage/dis-advantage of the cosworth manifold. However, I would either build the rest of the car out and wait for the F2 head homologation, or else go with the FRRP or swap the 2.3
2) Accusump not needed - though for piece of mind go for it if you want. I would think that an oil cooler (Focussport has one for $150 or so) would be a better first investment. However, you will need to upgrade their oil lines from hose clamp ends to a crimped connection.
3) Xcal's can be had cheaper than $400 - try Central Florida Motorsports or Focussport or others
4) Used 67mm TB's can be had for around $175 - see classifieds
5) There are better (though perhaps not cheaper) suspensions than the eibach. The multimatic kit is stiffer and not a whole lot more money
6) Get the Toyo R888 215/45/17 tires. The RA1 tires aren't legal after July 1. If you have them shaved, you may want to think about a second set of wheels with full tread R888's for use in the rain.
7) Make sure you factor in welding costs for the cage. Not sure if it's a bolt in, but you should still weld the feet to the frame of the car.
8) Budget $1k for a HANS or similar. NASA and or SCCA may require it for 2008, but it could save your life.
9) Personally, I think the Hawk HT10's are a better pad than the HPS. The HPS are really a glorified street pad. HT10's work much better when hot - more bite, less fade
10) Love my G2X - but it's a nice to have for your first year. Save the cash and put it into seat time.
11) Good to see if that you have the SS brake lines - they are a must.
Otherwise - list looks very complete - you've done your homework.